BORDELON TERRY JAMES (US)
US6795783B2 | 2004-09-21 | |||
US5552729A | 1996-09-03 | |||
US6977510B1 | 2005-12-20 |
■ 1; An e ' kijtr όiώc ckcuit : : : tό detexmiϊiό : a resistance valne-of a :; resϊstϊtfe ': ..element:, the circuit .comprising:: a. cπrreiit source coupled in-sfeαies with, tile resistive eferneήt,, the ■ 5 mirr.eήt source cdufigured.. : t& Ibi-Ge-a.pr'edeter.miπ.θ.d. value of current tliroKgh the ^resistive; element; aiid. a : transGθiι<iuctIn;g devieό;Gθ.ιi:pled.to the- curreiϊt source: εtήά : GόixSgιu'ed to s:e:Bδθ ' a ; γαiϊagi3 across the-.resistive element;, felαa; traiisconducting &viee;£iiii;hep cojiFiguresd to tmiisforih. fcMe vdkage iiϊtoaϊi. 10. outpitit current of the: .tr . an&cόn&.UGting ^ d.e%'Ice J: the outp.ut cuiTent not being dependeiit; upon san^ ath&x ierminal ; voltages -of the transcond^cfiiig deyie^.,
• 2. The electronic eircπit oiclaim: 1 wherein the- transfcondπcting device IB a- transi^toi'.
:S. The δiectroiϊic circuit αf-elaim : U wherein the transistor, is a lPMOSFET ..device.
.4. An eiectroftic circuit 4Q destermme^a resistance value of a: £ϊxs%: resistive.. 0 eleme.rit,. : th.e ; -circuit pα^β ' ii^iatig: a Erst-current source coupled in series with ' the first resistive eJetoent / thej.&'.st curfent spur-ee coiifigtii'ed to force a. first ' piledMermiαed. value of current through: the fiϊώt xesistiv«: : element; a .secόnά resistive 'element coupled in series -with the : first resistive 5 .element and forming a node; a secϋiϊdciuiTent source; δθtι|>l : e.d : to .the: fii-s.t cxϊrrent source;.. such that the Srst resistiye element is c.o.uple:d : therebetween, the secpnd. Qurϊeήt s:ourqe ; fethei' eάύpleά.m-s^riέs ' with the secGnd resistive" element at the .node, the second -current somxe configured to force a seeσnd 0 predete.i'mined value , qf-.cαrrentintό th& node; ;ψ.xιά. - W-
a-traii^c.θϊiduc.tiϊig device sampled to. :: both: tfa.e.;j&r8t current soiirce aiid the.iirst&βd seeόnd resistiye elements, ;the ti'kiχscon,dύctmg : φyie!e configured to -gense.% first voltage across the- first ' arid second. resistive elements cpupied;iti : ;.series with, one another,, tlie rtr^nsconductirig device; .5 . further configured to teaήsfcif m. thφ. fi.ϊst voltage irϊto an. output current of "the :txεmsedtιduGtϊng deyicfeji -ύa$ ontpub -cwn∑&ni not .being dependent upon. .any other terrαinal ypjlages of the: traπscoHductingxlevicβ.-
5. The ..eiectroϊϊic cif euit: øf claim ..4 whexein a magnitude of the second ϊO predetermined value ,6£ current supplied by the seepnd ciUTejii; source is', established sύφ ' that "a second voltage gerieratediateiOss ih® sedoftd resistive eleinent is GortStaήt,.
6. The electronic: ciϊcύit":Qf : daαni.4 wherein the teaiiscόnducting de^icie is eϊ If transistor.
7. Tiie. electrci.ϊiϊG circuit; of claim β wherein the. tra-αsϊstcir is a PMDSEET device,.
2U 8. The electronic ciϊcuitiof eϊaina 7 ' wherein- the second resistive .ele.ment is emiEgύi'βd to shift a gate.4o-sqtirce : vpTt^β of:.the PMQSFEX device hy a, fixed aniount-
■ 9, AIJ eleGti'.όnic circuit to. determine .a ϊ" ' esistaiice : -valύe of a resistive 2$ eleniQiit, the circuit : cρmj)rismg: : a current sotirce. coupled, to the •r ' es&tive ^i&M exit, the eiirretit source configured to force a predetermined value df current thfough the resistive element; a.first ty4M∞Mτtι.ctiήg de^dee coupled : to" the resistive eieriierit, the ZO. -.first transeoπdϋciirx| device xonfϊgui'ed to s^nse.-a Hrs.t voltage-, difference between a first node of the ϊre.siBtive element .ajicl a.iJefe . reii-cέ voltage, fest traήseondiietiftg devϊ-ee Si£theϊ Gθiifigtιre.d.to transform €h© &st voltage -4i$fere.nee- into aϋi-st autjrat e:urre#i:;of the fest t|ans.coJDtdulitiϊig: deyice^such tMt tKe fϊϊsj dtitput cmφ&M is not dependent ' upon any όtheϊ terminal voltages of tke •transeQiϊ.duG.tm^.d.eykθ:; sm&
5 a second .transco^ductiiigrdeviGisJboupled 16. the resist-iye; eϊθiiiθhte.
' tlιe.#øύθB«J : t;ranBcόiiductiiig d0ιύ& coii gurisd to sense -a ,søϊX3iκi- voltage difference, between a-.secoBtd node of tke^e^Miye. elemeat ; aπd : ike refe3rap.ee yplbage , , tiie segαnd transepndtictihg deviee furtlier.configtHJed to transfoxm. the. second voltage: difibϊ- fence: iiάifco a second output cuiTfent of the ,0 secQnd .teansconducting device sivcli that the second output cuixeiit iέ.øt depeiidejGt i^iόn-aήy otliei ' teri^maϊ Voltages pf tlie traiisconduetiiig device ' .
IQ, The -electroiiic circuit of elajm.9 wker.ein. the i-eference : voltage is βstabllsfe.d. to be adjustable mjaagiύtiide thereby setting a magπitrαde of 5 the &st : and .second output cixεrents,
II.; The electronic cux:tiit/ό : f cla;im .9- wheα*eiϊϊ the .first and second transcαnducting 1 d ' exαeeis-are eaeli a transistor.,
0- 12. Th(2.:electiOnic ci-ccmt of ^ claim Xl wKerein the transistors are. ,:comϊ)ϊise.d:.of ' FMDgFET deyiees;.
13» A:iaethod for determining, a value of. electrical resistance, the metHpd. comprising:, 5 forciifg two or more values, σf kaόwn.:ctιϊrent through a resistor
Gl ider . fest to produce twQ . or . more. voltages: gen rated across the resistiar.; adding each of the two or. mote, voltages generated across the resistor to: an adjttstafeie constant voltage, ^lierebs^I^ 1 ' 0 ^ 116 ^ 1 ^ " ^ W P Q^m^M TOϊtage,sums; - :2t -
sepai';ately -a|i . .p^kig eaeB..o£ : tlie voltage, sums to. andnp.Tiϊ of a. traπsconduGtiii g :dewice : gteiSemtiag a'.ciaiii'ent frσtd : t|ie tϊ'a.nscoMitάti^g'dievieβ baSed- on each of the applied - voltage. siimSj the/generated current ^.a^ying: g^.onerrtially 5 ' • with the iap.p.lied yoltagβ: S"uϊa;. measurmg; eath of ϊh.B value© of^ur^eat^goagirateXi By the- ti?ansco.n.4ucting device, at two or. more values of the Jαaow.n resistor cύim ή t; .and calculating tlie: value of electrical resistaftee ikόm ihβimsistoT under ϊ 0 - test . fi'pm : eaeli .of tϋe measured values. of current .generated by the tϊ^triscάiiduGtiiig device at two ^r.mpre. values όttJie ' kϊϊoWn: I'esistoi* GVLϊT&ϊLL
X4, The itijietko.d of ύeam .13 wiieϊem δalculatϊiig Um value of elecfeical 15 resistance, ineludes determiniiig a .difference in t : he- : iixe:a : sni ! e;d valttes of ptitgiύt current.
15.. :ι 3Phe method, of. claim IB -wherein o.alcxiiating the- Value of electrical ' $øijβ&rCcύ furthδririeiudeφ sc.aliiig; eaeh o£ the Measured values -ό£ current; ■ 20
16, Th^: ,m.ethqd. of. claim , 13: whereήi calculating iK& value- oϊ • elόqtrical . • resistarie&is iiidepehdent of an aBsoitate. magiiittKie of any of -thei valtte≤ of generated .tX'a^scoB^iiGting'.deλαce eurrent,.
25 17- The method . of plaim IB farther comprising ^selectmg a transcpnductiiig- device that has aii exponential tr^iϊsfer fttjicttbii of applied voltage to generated current. |
Bescmpfcipii
METHOD ANfi APPAϊt&TϋS FdE MEASXJREMENT '
5
TE&HMIGAL FIELD
[00.01] TM; present, inveiltiøii is. related generally- to electronic testing. Mot e. specifically, tϋe. present invention ϊs ielated to a method and apparatus for acQura±e mie-a : siuirøan^|s;of ' S-n^-i*e'aiδtance values.
iύ
BACKGROUND
[0002| Coiάto.pώ metHodS to " ttt64sώ*.ό- an electrical resistanee jόf &n . electtica-Iiy conductiiig eieϊtϊeλt; are.: (I) applying; ør forcing, a Mown eoαstα.πt;yoltage ac-ross the twp terniinals comprising tiie i*esiatwe;efeiB:e.iit 15 an4,me;a^ϊiiig;t]ie re&uϊtiiig ^lecfcsϊc : c.urϊe3i.t; and (2) forciαig a kjϊoλyii . , constant .current througli -tke: rsξvsiativQ elenaent. mid m©aS"ul'iήg a resαlting vόl|.agβ,$røp across- the elenien ' t'?. terminals, ^Dhe. xesistance4s, thiw de&αed as tke ratio o£wltag&..to cwrreήt inxder static (non-tihi^-vatying^ conditions,
2Q røθ.03 ' 1 Any. additional uαikiloWn.. resistance (e.g., wiring :Qϊ switches} in series.:wi:t.h. the resistive elepeiit contri^iites to the me,as,iired resistance, creating, a Source of dtrϋϊ. If : the ' resistance ' of interest is ήόt.nni<ili-.lai*g(3i v than sueh.additional parasit-ic- resistanGe/then an. aliexnative moihαάis erαplόyed which. relies όn.twό iadditioxial terminals ' wHclip^rforxh a
9. K sensing Ixαnetion (often referred. to ais a:Kelmn niethød). Fig..iAillxisfcrates a-.p.ribr.εuft approach for- sensing: the resistor tatniinal voltage wh^ii: fbr-cmg a Voitagδ 4^qss--tli&,rfisisti' ! fte ' '. : 6li-iin6iit. Mg; IB ilinstrates aϊiotkeϊ prior art.appiOach for sensing the; rqgis$or. terminal voltage when fereim^f
current across; the resistive, .element,
|0004] ϊh;Fig:lA, the/.-S$pped; voltage difference Vi- ^induces a current in the fest-res.istor.1.0 . 1. (E)- which pi-oduces the -voltage difference.
V 1 ' . -\ζ, . Tϊi€i: ¥όltagis:4iffeϊeiice i8 sensed byfαrciήg-ai negligϊbte cniTeϋt 5 thrbtigli e&ch sense terminal lie.-, mφέ terminals .1 fiiid ø)- and measύrmg. a resulting voltage øii t ' he sense ' terminals. Tte current> % βowang tlirougii .eitl#£ teϊmmal.l or iettmϊ%θl;2 is ineasύred,;and the test
I'esistaiice. dMei'iaitied. as E ^A ';1 ~ -PM .. Si2ice;ffegIϊgiBle .ciύτeiϊtis passing tlirgugh, parasitic ϊ? : e?sistance^.rήet)έ«i . ,cmd TMot < ύά2 f tEfty clo not 10 contribute significant erirtiif fe a .determination qftne current I. Nor do
I'sewse! and r S pή^^.iϊitto|iqρe a ; ..sϊg£ώβc.aϊit vo.Jfege drop, allόwiag: V 1 ' and.. Vg to be; directly associated witii YpItag.es. measured: on their respeetive. sense terminals. In- additioiι >: .ad<|itiojial parasitic, resistances ' ∑i &μ$. rg do ιιό$ impact the accuracy of .tK©; measiirement since V-I and V^. are sδn§ed X5: dkaetly,
[όOOS] Mg, IB viiϊiαstxates. arsimilar cό : nn.giiϊatϊόii- difiering ifirom. jPig x IA- only in that c^uiTentifLdWlng tHroμgη a test resistor 1.51 (E): curreiit $&■ ■ ■ forced ϊiii'ectly :by a .cm'i'eiife soύircβ 151 (I F ϊjbia^ . In hϋi% ϋoii : lϊgui 4 atϊoϊLS ? the ms^^urieaieiit :appatiatuβ inust ϊhøέig.ui'ø. the Voit-agSs: V^ έtad. V^. iϊi. 20 ' bi-dei- to dό'terinϊne; the rdsi^taiice of.tlie ϊfesistbϊt 101.
[0006] In the/event that, ϊhe parasitic resistances: l'l aaid Ti axe very large compared with .tλbte test redist ' or lOij .accuracy liiaitatiόriδ adse.. For a given force cnri'e.nt (lbms% or applied voltage Vi. -%, the voltage drop across the test r ϊeisistθr:lθl scaies with a prdpprtiόn4^ity ^fø ,. , . λ \. ϊf
2δ the -vci . ltage drop across theCtest resistor ' , ipi become sufficiently small, noise-rindnced voltage flnctoations iathe meastiremaiit system. can.. caia.se accuracy d ^ egradatioii : and/or long. r.e,q^ia:ed test times.- Test.
■ <® ,
insfcumentation cariimmimize Random ftααse error bttt at the eiφ.&nse-.al μsing time, averaging, techniques., thereby in.cr.easi»g test time, (often cόn:sidef;al;.bly) ; Resistance :iiionitόϊitig ,&p|>Hea.tiiόiisiii. ; : a pϊoduetϊόa ma&yf&ct.uiing . environment may not, be ρMe: : tα accommodate, a resulting. 5 ■■ re . dμcfcioή;i.i .tbiOtiglipttt.
[00.0.7] H.S,.Pat.eot NGS, ββl$M% tg (Mm : a.a# 6,.3.6:2 V 63S Aslitøn, et al, βaόii dφscϊibe ■^nVag ' pIieatH.pϊi. fot.ni^stsύting tlife iϊijerfacial resi≤taήcesφf iαtøgrøte.ά ciϊ'CT-ϊii films .which are, rep.areseiatatixre of.t ' lϊe pxøblein described- abo.VG>. Hoive.vøri. the vsma.U!iB.tei-Cacial?esigt; ? L : nces,are measxired wsipg a 10 force/sense: itieώod .whiiSiϊ must iresόive small voltage drops. Loiig test tiisθv^ can result to. countei-act the :advexse.. effects. of system noise, when ^eH^UiirigsMali resistances.
[0Q,p$J ^heyefore^ whaiis iieeded. is; a;H f lectriqal xesistaace me a^iirβmerit apparatus aiid. method oapa^l^ of both accurately lδ measuring ' sjaiall yalsaes .of: resistance andiή. a- tiine-frarae eondticive to- IJi>pd : u.Gfcioa;ejo:ia3.O^m6n.ts.. The appaϊ'a.tus.a.B.d method shoxxld furtherhe capahle. of acfcuϊ&tely rαeasuriϋg'the ' sϋiall.tefeisfcaϊice value i&. the -presence of serie&-e,pime.cted parasitic resistanee y.alues that xpay be .Qi'fϊiers .of ,iilagnitu,d;e larger than the ϊesiέtor ϋiideϊ". te&t ; -:
20
■ SϋimαiiYOF .THE γNVENTIøISγ
[0.009J In an ..exemplary • embodiment * therpxeseiit- invention Is.an ele:c ' ti > onic;.eii. v αμϊ^ to determi^ei a.re.sistanc.e yal^-e of . a. resistive element. The Gii'Ctϊit includes a cύϊreϊife sόtii'ciθ .ύOupϊedin series with the resistive. 25 elemeiit. The. current soiirce is ?Qniigiir.e.d jo force a. predetermined yalue pf curreήl tli EPiigh the resistive element: 'Xh&^iii'cuit further inteiii^es a ti"ansc.ondtictiiιg : . device coupled to- the' eurrer t fcsQ.Uϊce. The. tr : a.nή(2p3aductiii;g device is configured to sertse.- : a,yoltag:e across the resistive
eleϊήeiit and transform the: voltage ante aft output current; of ths, teanseαndu^t jng 4eγice svjcjh ifoa| th.e output ciirXentiaiipt dependent upon βϊLβ όtliier- tei'miiial voltages ofihe tτφxscϋϊiάπøimg. 'device-.
[00.10] Jn another exemplary ^^ ^iεLbG(^MeM > ' the present, itivexition is a.n 5, eiecttorrie circuit to determiϊie a ϊesistatice λrώiϊe ' of a :fbst reβϊsMva elem^ϊLt. The eircuib includes- a, .first eurrent-source. coupled, m fsexies: v f ith tlα4 : iirfet : tesiέtive eletti&άb aϊid. trpiifigti^ei t^ fc>ϊce a fir ' st pr^defcfeirmtined vaiiιa ; oi5 βttj * £en.t through ϊhβ. first ,xesisliτ\?.θ. eleaiextt. U second- resistive eleitie.β.tis.:cOupled..κi,sei^.s with. tfte : |h#. ■i"esistχy.e:.ele.pιø.ii4 tKtis fόnning ptό- & iϊødfe A second cijβfent source is cόύpled to t : he.#rst- : Gtm-ent source sueh. that the first resistive- element is coupled therefee&weeii:.. Tha seeαnd .Gμή'eϊ|t.;s;ouice,.:ts fύϊther eowpleά in. series witlt. th,& settoηd rβ$ϊsti ' vB eieiήent at the node and Is configured to ibfce a seeάϊϊd.pϊedeterniined •Yajuevof qtirrent into .th« : nød.e. A transcQnductmg.demce.iacpupleϊl bo.th to
15 tϋe : nr ' st ctirrent pburce and the; lii'.st and second resistive -elements.- The transcondueting device. is ccmϊigured tQ sense : .a.&st folt^ge- acroSvS έne :jSi F sta : nd second resistive, elements .ebupled in sefies witlx o.ne. : anpfciher and tfanslorήα ifaέ first .voltage in'toValϊ όtitptit ' ctirreirit :df tlie tfkήgcblϊdttctmg .device/such that the.piitp^t cm-xentrjs not..dep.eB;den.t.up.on.an3 ? other
20 -terϊiciiή.a.1 Voltages of the traiϊscoκduettøg..deviefc
[Oi)Il] In another e^emplaly e;iJibpd:iineiit, th& present iiiTOiition is an electronic circuit to determine a resisfcance ^altte of : a first . ' resistive element. The : .clectrQmc .eircuit: includes a. current sotirce. coupled to the • resistive element. The-ciirrent source is coαirxgύred to farce a
25 predetermined value ofmrreixt tnrough the: .rβsistd?;©. element., A first ■ trans-cόndiictiήg device; is coupled to the i-esist;ive:elfjiae . nt; arid is; cøn-r| ' gϊired to serise a-iiϊst ' voltage difference' between afest node of th& ■ tesistiy.e elexαent and:a relerenee vόliagβ, Tlie first tr^ansconducting deyioeis fui'tliei' Configured tbi transforrn. ffierβ^I'volfagfS dipga^erice ittto ' a
■ 3® first όtitipύt curiBϊrt όϊ the first transcϊiJiidttetog δevifee: sueii. that tlSllBi!
ouiput : ciiϊreήi xs-aot dependent on iύay other ferήiiϋal volta'geέr of tlife ti v aB:S.eoi3:dιi.cimg..deyi!efi;. A.second fcϊanscondHcting device is coupled tp-ij ] ie- re§£a^ye-elemθ.iit-:^n.^i λ s ' cόipL^i^feci; ' t<a sense ^Sfeeoryl yolMge dififerenc;^ between a second node of the resistive eϊeϊneήi:.and-tb-e reference, voltagev 5 The -second feraiiiscόii^ttcting de;yice i : g.&rilier coiifigured to transform the- Second volMge difference into, a .sβ.ccϋiid, oαitptit cm^eiit of. the ^ecoM. transcpnductiiig device snch thai the second output .current is not dependent on. &ixy dthex terminal.voltagesjof tKeføginsepnd-uctmg; .device..;,
[0012| Xn jtiiother exemplai^ .BiBfeodiment, the- present inveiitio.n is a 1.0 nietn,όd.fόr: deteϊ'ώiniήg a value of slectiieai re^istaήce-, THe ϊnethόd mcliides; foreing. two. or ϊnore values of known cm'rβnt tkro ugh a resistor
Under : : t.est : .t.G piO.dnGa;;t^:o or more, voltage s geaaer ate d across, the resistor.
Eacia όfthe two or More voltages generated actδss tile. resistor is added to aa.a-djiist^ble.: constant, voltage thereby producing two or more voltage. Io su33as\ Each of the voltage sums is separately i;applied to an input of a
: transconducting device and. a current from the. transconducting device is. . generated based .on each of the applied: voltage surna... The generated
Glϊrfent varies dxpqaentially With the?appHecl voltage 'sum. Bach of the. valtiøs of ciαrrønt generated by- the traήsøondύeiϊiig device is me-as-ured.-at- 20 Uyϋ t ό ' r mprέ" valu^ of the known regiβtpr ciirrent. The value of elee.trical : resistance is; calculated from the resistor taider -test frόϊή.eaeii of the .meas-ured.- values of current generated by ihe. traπsG.onclilict-mg- device at: "two or xnόre values of the ktύwix resistor cμiϊ&tttt
%6 BMEW βES.GBϊPTIQK OF THE DRAW1N0S .
[OOlBJ ^ig«.. ' lA..is an 'electrical resistance nteasmøϊne;at'.ciϊ'cu.it of the prior :-arfc wliiβh: : oρ.eχate|J: by forcing a voltage aόipilfa,r;|sistive eleineiϊt.
- β -
[OGM] Eig, IBis miotϊier electrical .resistance:- m:ea.surem:ent : :Cir6tiit : of the •piξiør. ai:t whfck operates b,jr forciijg a,c;u,rreiit across a resistive, efem.eati
[G&lδj Fig: : , ' 2 is an θocemplarl: eieetiic&lrssistance- .rάeasui'eϊnθiϊt circuit in aecprdaii.ee. with an Bitibodimeiit of the present invemtiop,.
.5 [00 : l6] Fig; : .:3.:is an exemplay^electrical resistance.: measurement; cjreuititi .a<3QαrfeLance.%itii atiotltei' embp^iBiejiϊt of th& :ρrfesent -mv^tidii,
[0]QX71 Fig, 4A is:.aii exemplary, electrical ϊesistaμce meas.m'em.eiit circuit; in. aceoKjiaiieB witϊϊ axiotlier erabpilim . 6 ^ ®£ ttø- pfθsent : iiivθijt|ø ; ii.-
[00183 :.Fig- 4B is a modified yersioή of tliβ ©xemplarj embodiiiierit of ' Eig, 0 ,4A,
[001.9] FigL 5 is . . . aft exemplaxy electrical. resistarιqe;..ftiea$uM aGco.rdan.ee with .another embodiffiøϊit of the. present invention,.
|0:020] M|. 6 Is anexemplaxy EoWchart iiicHpating pi. e£8x$$ki$)MQ$ip<i in aceerdaiice. withvan embodiment of έlie present inwisjiiioa;
:5.
-D]EmI-LEI) DBSCϋϊP.TϊON ''
[0:0213 ' With Xβf&ence. to Fig. 2 3 an eXfemplaiy electrical iesistanqe :meastit*eriaeήt-tesb ciϊcuii. includes. a. resistttf under test 201 having; a : : ϊeaϊs . tance value of.B, :a Erst parasitic eg^iValentresistor^OS having: a 0 resistance; value of 1% a aeeond parasitic feqxxivalejxt resistor 205. having a • I'esistaiice vaiμe of rs, a firøt sensing trandsior !^Q7 (M 1 )^ and a,ftrs| current, sdurce 209 having a..st.atic;ciirrent. y I b -. Fig. 2 ' M mstructϊye for- esplkining fundamental operating principles cOBimoft to aE. βrαbϋdmients ^scribed lue^eii?.. The resistaiϊce valtte,- S!.: øf tlαe.resϊs.tor taiader test .201.is 5 ' to.B.e :me;ά.s.τirMv : TJiB fest :203 and second ■ 20§.piar4:s . itie e^iϊivlilerit
: t*βS.isi:ora ac.CGtϊnt &>x valttes: of:ϊesis.t.aiace: .^sSOθiate:d.witlx eixcυdimratig,
coπiϊecfoϊa, and asiy switches present le'ading to * a measui-e ' ϋϊθnt instrumentation.: device. (not sliow^i)- 1» a;sp,eciEc! eχiB : nτ!:|3la.ty; βmbQdiiiien^ thθ%^.-sdrisiiig.traasistot : 2Pf is. a . PMQSFET dencB,
[.0.0^2] The -BXeIiIj)IaItT. electrical resistance meas.uϊβ.πifitfϊt; test eirciriϊ. of o Fig. ; 2 i ' s : |>articula:riy- adyantageous^ when . a?f . elsisfcance valtiø R of tijie resistor urideϊ te.st,20.i is mxicli smaller than, se.paa'atβ. oi ? coMbiiied i:esisfcaiic.β:yaKιe^ : όf thό : βrst .203- :aiid secGixd 205.β4i-aβi.tic equivalertt- resistors. Iu tins case^ .direct- measurement; ό£a voltage- 4^Op aciOsS tlie- resistor, tinder test -201 by a foiWseuse , method (as .described above) .can
ϊ0 beeαme iiiaccurate Itέd/oi time consuming diαέ to t!ae-,srαall size of the voltage attd its concomitatιt;susGeptibility to noise. The exemplary electric a.l:i;eg|^tan:fie measurement test circuit. transfoim^ tlie resistia.iiC'e.E. of tϊie ' resistor :tϊii : <i#r; test 201 . into a. current (I) at te^niiiialVa WMctiis IeSs susc.βp.bilale to the: acemraey and measurement. time Mmitatioas :θf jptfior art iδ approachesi-
[€|02βJ IirPi^ %. the εxβt sensing transistor 207 :ponyerts :a g:at©-to:- soϊii'cfe- voltage iϊito dr-^in current L Sirice ' t ' ϊia fij.^t cui-i ? βnϊ source 209 foϊGe s- a . kn(iwn current Ib thrdug-h .th.e. resistor uade-r test ' 2QIj. a magmtiαcfø ,όf gate-tQ-soύrGfe voltage- of tBβ.fi^st.sensiiig-tϊmnsis
%ύ. -ø£.% aud fi (iieglectirig-- any .le-a-k-agδ current ttoough : ' th& : §ate of tlie- ϋi > st ^n.sing:.traπsiβtø : ir5 : 07). ; ; The sqiirce and drain bias. αf-tfre- UrStVSeHSiIIg- tMiϊsϊstόr-Slό?, clet^ir^iiϊi:ied by terύiiiials Yi.an<i Yt resia.e^tivelS'', is set su&h tliat the drain current I -is modulated only lory the gate-to-sαurcia voltage. Th ' e. gate-to.-so ' vU'ce voltage. in turn depends only; (Oή.Iy.aήd.B. This iβ. iδ adconiplislied by; selecting the source voltage. V^and dta:iή voltage V%- of the transistor such that
V 1 - V 2 ^ ■ —
and
w;kere,lc.i.S;.BDit2maim's constant (1.3809.9 X iø- 23 jpules/°lf)y T is teMperatxir© ( ώ E), q is^tlxgi electrpmc-ch^igβ ;(1:6Q21.8 -x JO' 19 eoμloHib), and. Vt Is tliβ tliresiiold. vδltage : of ike .first s©iisiiιg-tχ%ϊisistoϊ 207; This biasing 5. arrangement places the, first sensing;. transistor 207 into sufethresboltl cdMuctϊoil with a suffacleiitly large ■ dx'aiivt : θ^ . Qip?.d : e roltago; sucHlKat the draϊή ttii¥e:iit I do.βs not dόpfeiϊd on the drain^tq-solttt.e voltage . . ( ψ^ - ^); Th.us, the- di'ain Qμrreαt is.ixisen.Bitiye to the parasitic resistance 1'2. OH: the άrέtiϊl. tδrMinaϊ (terhϊmal ¥3). !TIie .dram current 1.8 also inseπsitiye tQ : ihe; 0 χ>ar.asitic reδistaixcBϊi of the sondes terminal (terminal %ι) : giϊϊ.ee tli6. drain ' cui'pa.at does iiotiiiiEluenGe the :gate-to-source ; voltage.
[QQ&41 Wiih:c.oήtxnuea.;:refer.ønβe tσ^ig^ ^ la s^bthresliold øp:era;tibri : w ' ith.a ^ufficieήtl3^.1a>g#dr^ the draϊri ywrreiif of vthe ; first seiisiiig transistor ^Of i^ given, by:
I- R^ 4 W
•vyζhθrje. ^ . ~ψCφ #a^i K.ls-.a..bi.as-indej?eκ4eiit pi*e.factor ^vhich idepeiife : uppπ. the size, threshold voltage ): and. other param ter's of the first sensing ttatisislϋr -2Of -WBIpIi deteilHine ; the ^ttrrent drive of the firp.t S.ensiiig transistor ?207.
[002δ] Dife-reήttøt&ii the .dr ' aim current I with respectto cύltfeiit h yields;
B I «,] J
Thus; E.can.tos; ύl'tgirήii.nøid: by meaisUKirig the έlope of the natiiraJ. logarithm of draiϊϊ:.cu3?r©nt I-.plotted. as & :ruήctioϊx ; όf the Bias : ctiϊrent Ij,. (jand sqaled by •a.fac^dϊ . of ^ Tt ),- T>$B; tp the^Xpbheiitial l±atoi'e of 1
fonctio.n of Ib > tϊie Bias^nSep.endertt pϊefa&tor K insfeϊi :ϊi<3it fo.e. kiaϋtøn in order to extract the- value.iøf $&>
i&02 * 6i ϊhe 1 ability to -extract, the valύi?. of R-. independent of tfe. dϊain., qurjen.t-s>jcef^ctόr:Jζ is a sigmficstiit advantage, since; |Ke/.B.rop^rtiiBs pf tho • .§ ■ first sensiiiig: tyaήslstox 207 » -or fhose. of . aaoth.es PMGSEiST similaϊ tάr^he BxBt sensing; tø'&iisistor 2B%.- ψonM.mdϊπ&vily, need to be measured in ©itdei 1 fco: determine tH@ Ϋξdn&StK. If the £t ; rsfc S6 ' &ping/featisϊ§.t^ϊ; 207 : itβ&lf .^.βri* to -be measured {Mreci%:io ' idetermme : ε, the n an©tiαeϊ ch-cmt esoϋfigiiratiαn w:Qϊild, ] ϊe needed • sιiβlα.t|kat-.a 1 l∑;npwϊi YQltage. eo.uH be. applied dipeclly. to the
10- gate of the first sensing; transisϊor 207, $ueh a.ine^si^etiieKt.woiiidsu^i? inacenracy in tlie.gresenee øf.non?:negligible parasitiC:resi.6tanceg.(e\g:., π WLidm) ' , and degrade: tfee acjjul-acy of.the method.. If a.. : differejat PMOS^JST,. •similar to. tiie..fiϊs.t sensing ti'aiisi8tDr2G7 but cohnβGted tό thδ tβlst instrunientatioii witko^fe. §igmfieant. : p>arasitic series resistance, is used-to,
1.5 deteriaine. K, then. aii^ .migϊnateh. ia the drain cutreήt between this device and the. first sensiiϊg.transϊstpr: 207 would degi*ade : the accuracy of IC .and- . hence the accuracy, of the R-λϊalue extracted.
[0027] 1£ both :ike 2?Q&ist0.ia.ce. R and the -.current h are smβSX^ihen &e; gate-tq-source YQltagδ ;έtn.d,.the re^ultilig drain cιιrr#.nt : will also B^.lόWi 2.0 Fig. 3 pr.ovHes a mechanism far adjuStihg-ox tuning the magmtϋdeí.αf. .drain, cμiτeϊit I bήce -fehe; circuit is^iponstr.tic^ed,. thus j>rpyidmg for an v optimally accurate and eMcient: measureiaent-
[0028] In Fig * :-3-, anbtlie. ' r exeinplary embodiment includfes- the cimuiiόf Fig. ' 2-pltts a second ϊesiB.tots 301 having a resistance ' value of Es aaad-έt 2δ second purreαit ^usce $03 providing a static current of.ϊbs. The .second, resistor 30.1 and tlie ^ . eepixd current, source -SQS are used tαshiffr-tM.gate-- to«s\αuϊ.ce voltage oϊ.thβ first sø.nsmg teaiisis.tqr 207 %-a feed amoμϊit. The additional ebngtanf g . a;tθ«tc>-sόurce volta,g^^ 3 ^y : eis v tQ-^ipe'th>;.^ai&. cπr^entnvithόut^clmtigmg: the sensitivity of the drain ' earreaat ' to Ib, ^sCϊL-,..
-M -
A .constant voltage is created -across the seiecjiidiϊsiδistor 3QI by:fecirig: a eemstant : :cm>rent thxougkitof value. Ib^ The constant current; is- acdomplisk©d^s Xbi# Yariecl by fάfciϊig a-etirrent of vklue (ϊb s - 1 Ib) ' in tb.e seeαnd : eurr,ent source 3θ3 ;(as;lo3i : g ; a!S tlιe : resistance value, % ? øf &e, 5 second, pesisiqr Wl remains constant)-
[00129] In tiie:.eγeiit.tEat tlie,flxst.se.nsing transistar 207 ejihilsitSλOrj.-
■αchϊm&d,hτ&esoύi)mg%h.e first sensing transistόt 207 current a;s-
l : 0 where B. HθW possesses a- wealt dθpendeiζice oμ the.3iive ourrisnt I; . Irs. this; case>- the first sensing transistor 20.7 (or a,skailar deyicø) : must first be imeaswred iή : :a ^separate te§|.caafigur-ation to extract B -as a-function of L Then, when;! ia measured b^f the; present iiivfention, B(ϊ) i§ readily cal.cvilaled, g.ud analysis ..can proceed .as d^scidbed above iisiaig the value of
15 B(I) pre iously obtained* ^^^ < j pritainmg tlii derivative of B with respect tc j .l {ie. ?:: I ^ ygF|j) ' 4$® ixW^iW, ignored rα the exti-actiph of K.
.lcpm I in. fehis case. ' but to. a/^ood; apipi'OxiMataoil for PMOSFETs eicMbitiri^ n.ørmal .qxiiT.ent-voϊtagl eliaract^.ristdcs:.:
[OOBiQl With referenee tøϊEig. 4A ? - a tliύ'd ^arasiiic equivaient:registex ■20 401 Iia ; ving : a ' resistance value of ι% a ^ fϋui^h p^rasiiic øqmvale . h.t re$is;li ' (3r : 40S ' havirtg a resistancis value of ; £ϊ, and a second sensing transisto 403 (ϊVl2) are adiied^iid iisedWith anvadditionaϊ terminal Vi to enable adjti≤tinent of the gate4o-so.a.ixe " ybitage.όf the : fLi*st seiising ti^aήsistor : -207: In a spe.cilic •■ exeMplar•5•^øm ■ b.ρdk-lent J tihe λ seGθϊid seiising transistor 4OE is 25 a PMOSFET. Tiie voltage, difference .. . (V 1 . ~λ?a). is siάάefi directly to tne
■ gate-tό-sourG.e ' .Ϋόltage of. the iii-si. sensing^traHsistόr ' 207;, thereby realizingi ■ an ability fe tiine-.^rai∑i enxrent witli the. second senssing tranβdstoi- 40B- rj instead of with ' the βeftόnd j-esis ' tόr SOI; and,tb.e a-dditioual όuxϊeint έwέM
303 of the emboditaeftt G ' fMgi & όόήseclHen.t^.-άneilegs eurreni.soutfce. fimetiøn: is needed in ^a--^e.^^θm^ntαnstrijϊ)a-entaτ(;ϊθ-i utilizing the- eiribodiπaent of Frg. 4A: f
[0031] The resistance:. E is. e±β acted! in a m#maer similar to thai described ioϋ the exemplaiy embodiiiiβrit of E£g.- : 3, ahovie, Refέsrriϊϊg again- to Fig. 4A, the. drain curr.eiϊts of .b.Qtii ihe. fixst, ' .207 : and : the.:, second 403. έensiiig fcransistbrs ^aupe^iaeas^p^^X aiad .ϊa, respectively-., Thφ fwki 207 and tte second 40B sens : iiig iiiaiisisto. : rs are both biased iiito subthreshold όpei'atigh as with, the,em:bodiment s&t fbi't ' ii. withxefereneg to Fig. '■ $ ■ . The. difference i ή .: : -gate-to^sourGe 1?bltag$ feetween the ' firs|. : 2.07.an:4 the second 4Q;B- sensing; transiatoi-s is (E.~.I b ). Thus, the ratio of dfaiii cύτrents.is :
JB-I^E]
witia a notation consistertt wiϊhjhe equation ^reβentedjhr. ihe :^mbodime.nt of Fig, B and whei^iKkls the dram current pr(?:factρr;Qf the, -Se.eond sensing teaiisistόr 403; The resistance- is exfeicted as
E,
' $. In rUir kin ^a
: α^: i • L4j K.
li ;
o lή J I
R - 1 - I 1 ^j
'L^b-
in a manner identical to that of .the enihodinient of -Fig. 3 using- 14
instead of L, ¥alτies of ;1E£ ap4 Ka-n^^ji notl)e: : identical; ;only their- ratio must- De.i ή dependeήt.of ' U* The-anaitsis teiαain ' s vaMd : as- long as t^ill-it.
.207 antibthe seco&&:408 sensi3ig:t : raήsϊst : ors,:exMbit idiϊg: channel, faiilfe device Behavipr: : $-αdh tiaat tii^r siib|hiTesih.ol<i;sI:opes.ai'e : similar 1 :.
|pθi2j ' Eif> 4B;.§iiow;ai ;an additlόnalfeatάϊϊfe-wliich-.m^y be employed to. furtjiβx adjiϊst -^ TheMdy of th^iirst 207 and the
5 seco iϊd ;4θ&-seridhg:: transistors rtfay fee. biased iii ' dislseπάbnt .of tlie comttrari transistoE source- to. adf-ust the: : thi'es-2old yoltage.-of e;ack.tEansistor..a.xid iϊisnte tiie : drain 'cϊφέx§nti This l?ia;smg όf£&t siari Additional, degree of control for oplima% iscaϋngrfcliβ drain : cmύ'ent h f applying a forward- ©r r$yerse $ody bias-.:
10. [0033] Eefemag now :to Fig,.0, aao&eϊ altei'natiye exemplary έϊiibb.diπiθnt uses, a^ipόlaf.tr^ϊisϊsfoϊ 5Q : 1 iβ§tea4,Of a MOSFET (e.g v , ih& ' iixst sensing- transistϋϊ 1 - 207. . Figí ≥). -In.^ Specific exerriplary embodiment,, tlie- bipolar, transistorβ ' Ql : ϊ$ a FNF transistor * ThB. bipolar transiBέor SOl is biased ϊϊitd fbfwsLrii active rnαde whei-e^the collector cml-ent; exhibits a;
1-5 isimilar eKpoiiefttiabl diBpendendeioit the basόj-toreiήtittervoltage.. If the
■ e^it ' tβr-tp-GDπfe^brΫpltag^ ^ ^^ ^ tϋiittjb. Xalcger tJbiaH ^§ζ >: tϊie;n the collector-
feHrrent depielids όli ' the base-emitter voltage as
■wh ! i3 ' re K; is a bMs-ϊ3adepiB)l^jBn ' tjp^fø^{ϊr; : UMike $i& JMOSFBT iπ BQ ::SBbthrgsiiόld.condτj.GtiQiiy thβϊe is via basaicm'i^nt iii tlie bipolar transistor, 501 ' -which., may .be comparable in rϊiagriitύde. tt). th^:c©He.ctor current (if the- ■ forward gain όiiύϊe bipolar device 3,s-. 'ή earMiMt$>|).. ϊf-jiiasa- <κ h» howev.er;. ■ then the- bipolar transistor 80:1 in. fQ^yard ae ' tiyg,iϊi . o.de allows the -same • extraLction :όf resista-rice E : as ώatB-^ploy^ ' ^Yil^^^ ' ^^^-^ i- 13 - : 25 siibthresliold .eoiϊductidn,: namely.:
1 .f 3|Wifj
Any. error incurred due- ' to Ibase .& ^ simply
B(aCϊiιal) ' t b
t ' ri : ffi&ny applications, Iκme wiay/ be Iwό-to three. orders ύ£ magnitude: smaller than TH.
tι.
[0034] Various. embqdϊmeή|s : of the oresent invention jiaay be ήέ&ά. ]?y appi^ing- BuitaMe voltages and currents iύ tlie circuit terminals and nieasuidng.tlie..resulting drain ;cwrreni : I. The resistance R is then
ID caic^ilatfeϊd by methods descmbe4 abwø > Giuxent SQiά'ce^ Bi&y be impleraeiited as connections diractl^ to external measurement: apj^r.aius, or to cuϊϊteήt mirror circuitry with svtiέable ' bi.4siϊig and control inptits. θne.όxemplary method of opei^ Mote that tiifcmeihod is exemplary only but a person of ordinary skill -ϊa the art
%β woήM teeqgnize ceλ'taiiα nlodifiog-tioiis tliat. would, still be; within a sGope of ■ the: pϊαsent invention. Theϊiefόrβ, -iaϊnh όiliMeiits df ' tlϊe : ..in.ventiQn-. May -be jDperated.:in a manner differing from th^ following .seq . ueBee. > : ' b.ut ' preseϊMng conditions- fdr prθ|> : er opel'Sition ' as ds^erib^d ab'0.v(5; .
[Q035] Referring now to Fig. β -aiid rθfe3?riiig.hack to Fig. 3 ' , ajo... 20 exemplary, fiύ.wtihart 600 preseiits: : a method of ^ne ; as^^ϊ^ng electr&al resistance utilizing one. of the VaripWs circuit . qrabodimeints desciibed. liersih.- A skilled artisan, will. re4ogniae : . ψhicil values χά&y rieed siibstitiitiQn.based βϊi, for example,, the type of transistor selected itϊ the; meagiu 4 eiiierit circuit x [0.0 ' $6] Initially, a..user- will: ^eleet. β OJ the . magnitucie desixed. for- φ-ain Ciirreii:t:.I.ba|e(i QU . accuracy eoήsideratibM
hardware. ,A v&iάe..of gatevtα-source voltage iέ estimat&d, 603.that is, needed to, achieye, ' tlxe Seskecl .magnitude ώll bas$$ .oil an approximate ikrio.wlfedge of teansistdr- ' Ml properties. A. maximμm.ystlue ϊor bias, ctm-eiit. Ibis set. 60S based on (a:) a desired gate-td-sόarce voltage (Vgs) όibtarάed 5 from. th,e preceding step 60S 1 and (b) aii<aρprακimate.:'yalue of the, resistor
R aiidrfcke relatioϊϊ .^(ftiax^ " ?| % ,
[0037] -A value of the .mimmύm forcfe-cxirreήt? pj»in| ia selected 607 sucji. that the valpe isvgreater than- the leakage curreϊϊi flooir of the : measiii-emeiit apiiaratus and tββt enviiOiiineht. The/cuiTeiit lb s is . set 609 10 such th.at:.ϊ p = ϊ^ iti -fϊ^^ϊiax) . A value for starting curreiit ώ selected 611
.sucktEat. I^ > ϊ mih . , YόMgeS:før. -V* and Y& are forced .;6.1.? sμch,tha.t Yi.=
Vd<i andλ^. ~ 0, whem YM is:t&e maximum φUppiy) voltage,- Current ■ valu0s;.ar^,.lbrce.d 615 seqαxe.ntially; Ib then Ijb. s - l$,χm the ilrst 209 and secoad 30$ curi^nMDm^s ^ respectively ' (Fig, : 3},. ; Current. is then .IS: nafias.arftcV 61? on teranirtal -Vk
[003^] : Tile: v,&kιe.ό£ Ibis- then i∑i.Gremeήted 61©., A.;&terϊϊiiτ3:a.tion β21 is m&4$ whether :\ > I fe (m^|. If I^ ^.^{iiiax),. step:s: ; 813 — 61:9.are.i"epøai;ted λϊiitil I h ' ≥ %(Max}. iEiiiaii^, the resisttee^ value R m&y be extracted 4ire:αtly in, accordance witfh the: gQvexmng e^ations discussed abov:e. where m H.iø- thβ..Blφe : of ln l^ plotfea againstii, f E - y£g :&έ BJr)I ' .^
.røO.SB]. Steps .001. --.βl.l may lbe : -applie.d..d>mng-'the,:q^ i>ih,a.s:e
: so tliat the vahϊe of i-e&istbr Es is Selected. as
lt ώ ^ (H ^ rlbfea^S
^b 6
wiϊerø jE^is-όjϋ eistiirtate of ϊk& value c>f fesistiof iR.
A&ύiϊrviages ofJBmBσdinϊetϊtb of'thelμveτitiόihp,ver BriprAri
[00£0| : Nuiήsrous advantages are-^^^4. : ^Q;m ^ d : SS!^iptii0''ia'S: of 'the present iiivaiιtϊθtχ:s©t:fόrtϊϊ ^ Mfeiti ^ GQU|)iφ^ i^itE aϊϊy ϊϊi(ϊdifi.catipns : :tp. em]bθ(iϊmeξite .Qftfe.e invention recognisable ' By a skilMϊi -artisan. Amt)rig-; fclϊes.e 1 ' advkxitagøSj the embodiiridhtsii .of ' the; itivention-allows- -accurate. meas.uiNsjnient of- a s:maH : resistance iii series. witE^iφ|i'lai?'|ι;e-*-..uii&i ! iό)w^ι. pέtyasilϊc resistances. The. sxαall resistance is-acCteratelv rjjgasured foff- s&ti&htφmi electrical- cntieϊϊt oil a terinitial whose ^plfcage,dpe.s; not need ;ϋo. Be known. Tk& m^gmhidfe of the sensed citiυeiii is adiύstabfe to a range . suited fof op tiiaal^easui ^ emeiit a.Gαn?g.cy; A.^plla^e meaaureiaieiit ls not ne*3{3M as reguifed " b^ths;pi*io-r βi't, tlras eiimiϊiatJHig accwaG^ Ii|aitatib.fts .due tα voltage noise ψ}χexι m&SLsnsmg .smaϋ voltage ,diHei*&nces β liai^eteiistic of.smήll tesl; resistances:, JPiirther . , the accuracy .of the sense current is -UOh depβndemt on. the size of pai'asϊtic eries: : ϊe^istaώ6eS:.'πGr Ia tϋe acGtiracy - " of : tlie . se^ge. øuyrent dependewt. on. the .emTemt drive: strenfth øf donstittieni transistois of the: sen.se. circuit.. .Smcis: neither the . siaej.of parasiiie se.ries : ^esistanc^« nor the etαa-eftt drive strteilgth of coiistil'uβϋϊ.. tf;aftsiB|Dϊs afe ϊeqtiiϊed for moasiirement, (iliaj'actepizationvof Batøi^onneet wiring, aiitϊ sfeixs : e.:cireuit dό^ic&ή is Hot needed; • GόiiseqύeMty, the a.e . curadjr ύϊ ^tr.;|#;ed i'βsiέtantje is ; dep.enςtent only oii.fehe consistency of -tJbe: exponential nattiτe.-όf:the ϊest circiiit trMϊsistpr . eμii'eiit u&dei appiOpriafe bias G,oii4itip3i.s /:
[00431] Various- embodiments of the. iiaveiitiojl pr6γid.e a method and . dircϊiit appai-atus for accurately extracting the yalue of a small test resistance iii : the ρresence : of large, unknqwii .parasitic r.esis " tances in series witli tjh.e tesi; resista-aee. Suck a scenario, is ^commonly encountered in cIiaTa'ct^riKiiig lhte^perfόrm^ of integrated circuit; elements,, wkere;: iiit ' ercόnneer rfesislaiice aiώ switcϊi resistances ' can be rela ' tϋ^ly very large, TtiefiriΫeήtϊόn .tktis:.;a^oids,disadyaiitages of:.G.oinm<3i£ily used foree/sβase ^ β ϊx^;iiie^ό4^.:Sϊ*Glα -aø Voltagø noise SusceptMlitf ®nd ' sdftέa.lέaJl^pll
etesjeiit eirαi 1 .- The- iisvβntibcή. effectively traiisipirms the. tø : st resistance- into a Giirrertl;..wMiBh; can he sealed well above cii*gα-$ leakage levels ύϊxά ϊMό a i^aαge best suitθid.fθi 1 the imeaβuremeat matiimieiitafclon., As a res lt, fastei' .aiκ|.niore : . aecurafø me&stirenients of small re:sista ? ice afe possible i& • 5 ' the /presence pf:parasitic resistances and measurement system lϊoiseL
Fabrϊcated as an fa£teø;$.t&ά circuit, embodiments :pf the inye . ntipn allow .muqk,greater density of xesϊstox test. structures than: traditional fbrce/øβn# tάst : :sti-Hetxιre.3. Area-^fficiertt . multiplexing techniques which ntroduce: series resistance and leakage c-urrent caii b.e utilized without 10 degi^atilng the accwacy of small resistance measuremettta ^
[ Q 042] ϊiϊ the foi'βgdiiig specifieaMon,. the present/ iήyeiitipia has heeή- Ufscrihed with ϊ'efeϊenQ^ It will, however, be ^ e y icient to a . skilled artisan, that various modifiGatiqήs ahd φanges can.be m&3,& thereto: witho t departing from the- brQaάer spirit m.nd scope, oϊ the:
15= present . mvøiit ; ϊoh. : a-s set .forth lit the. appended ekims. :For example, all eaiHbodimentg deseribed utilize 'p-typβ' .tr^ixsiltdi' ^lewents. Each .. ethbAdiotient can. be : xe&άϊly teansfornsed into , a ersioti: WMch itses 'n-.type' traήsisior elem^iatsiii a sti^igHtfofward manner 4p . psα?ejit : to- one sjαlled in. thei ixχ% of basic :,transistσr økciiit dδsigii. A scope of the- preseϊit iiiveβtion
20 ' co^eϊ-s siich: eases. whiβH ate^oiist^Ucted throυ.gh. simple, polarity i-eversal of voltages kϊid.ctif rents,- thereby, re tairiiag the same : ;claiffct§ a.S. thfe iήvqiitipn eϊτo ; |>.odii|ieiit.s .described in detail Further, -other lϊoή-ϊxήe.ar eoϋtrol devices besides those shown can.be ulsed to realize basic npn-line . ar pehaVioiiia tEe eircμiti;^, Additfenally.,- a skilled artii5£in.\v.m reco:gjjχ^e thatvai-iousi^pes of
2δ transistor tepMόlbgy. may be employed iQϊ the yax-icais emfeodiment^ desciihed, herein.. *Ehese other technoiύ^es.toclude .^ /for example, Bie>^QS } DMOS, .Qϊ: other trauscoiidtictiiig clevice eircmt-ry,. These- tech3o;ologies;»ia:y be implemented m ?: . for -φXamplfe,- silicon or QtMt el^møhfar s.ea-nicQnductQrs,. G)t-o.up. Jπ- : V ": orirr : Vϊ cθ33jtpo.ιiω,d s.øωicoήdχictor% : afid vaiious ailoy ' i? thereof- 5r
30. y.aridits sttibstratfe tf pes kxxβt as silicort-oii-insulator 02 1 . even ..n.oia-st
siϊbstrates-.suefaf asJa pόl^etiiι.^le3xetere|>lhtlialate (FET) feύbfl>i ; ate. deposited wiffi silicpn dioxide and polysilieoia. followed. tøy- an exβimBϊ.ias&r ansiealing $MJty aiiiieal step^ Each, of the^e ;feeMιdlpgy t $ ψβέ- and . jωtM^pais axe τecoψάz&bl®. to a sMlled artisanv : These ' aϊid.vsέxious: other embϋdlmetxts^ai-e all within aiiβdpe Qf the pr^sent inyentipiiv The specMcatiOiL ajid: drawings atfθj, acdo^dmgly^ to; foe. regatdedim aii illustrative rather thaii. α. restrictive sense..