Title:
MANUFACTURE OF SEMICONDUCTOR DEVICE
Document Type and Number:
Japanese Patent JPH0685201
Kind Code:
A
Abstract:
PURPOSE: To lessen a level difference between a memory region and a peripheral part, by a method wherein a well region forming process where a memory cell is formed is carried out before a well region forming process where the peripheral part is formed is carried out. CONSTITUTION: An oxide film 22 and a nitride film 23 are successively formed on a semiconductor substrate 21, a part where a P well region is not formed is covered with a photoresist 24, and P-type impurities are ion-implanted so as to form a P well first. Then, a thick oxide film 25 is formed on the P well region, the nitride film 23 is removed off, and N-type impurities are ion- implanted into a region where an N well is formed, using the thick oxide film as a mask. An N well 31 and a P well 32 are formed through a drive-in process, and then the oxide films 22 and 25 are removed off, whereby the P well region 32 is set lower than the N well region 31 in level. Therefore, even if a capacitor is formed on a P well region in an after process, a level difference between a memory region and a peripheral part can be lessened as a whole, because the P well region is lower than an N well region where a peripheral circuit is formed.
Inventors:
KIN EIHITSU
TEI YASUE
TEI YASUE
Application Number:
JP3633893A
Publication Date:
March 25, 1994
Filing Date:
February 25, 1993
Export Citation:
Assignee:
SAMSUNG ELECTRONIC
International Classes:
H01L21/8238; H01L21/8239; H01L21/8242; H01L27/092; H01L27/10; H01L27/108; (IPC1-7): H01L27/108; H01L27/092
Domestic Patent References:
| JPH04271168A | 1992-09-28 | |||
| JPH05275649A | 1993-10-22 |
Attorney, Agent or Firm:
Hattori Masaki
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