Title:
ADDITIVE TO PHOSPHORIC ACID ETCHANT
Document Type and Number:
WIPO Patent Application WO/2020/097778
Kind Code:
A1
Abstract:
Embodiments of compositions of a wet etchant and additive thereto for selectively etching silicon nitride to silicon oxide are disclosed. In an example, a composition of an additive to a phosphoric acid etchant includes an inhibitor and a dispersant. The inhibitor is absorbable on a surface of silicon oxide and capable of inhibiting etching of the surface of silicon oxide by the phosphoric acid etchant. The dispersant is capable of reacting with a by-product of a reaction between the phosphoric acid etchant and at least one of silicon oxide and silicon nitride and reducing a viscosity of the phosphoric acid etchant.
Inventors:
XU RONG (CN)
SUN WENBIN (CN)
SU JIE (CN)
SUN WENBIN (CN)
SU JIE (CN)
Application Number:
PCT/CN2018/115124
Publication Date:
May 22, 2020
Filing Date:
November 13, 2018
Export Citation:
Assignee:
YANGTZE MEMORY TECH CO LTD (CN)
International Classes:
C09K13/04; C09K13/06
Domestic Patent References:
| WO2018124705A1 | 2018-07-05 |
Foreign References:
| CN107345137A | 2017-11-14 | |||
| CN108690621A | 2018-10-23 | |||
| CN107573940A | 2018-01-12 | |||
| US5429673A | 1995-07-04 |
Attorney, Agent or Firm:
NTD UNIVATION INTELLECTUAL PROPERTY AGENCY LTD. (CN)
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