Back to results
US 8,999,850 B2Granted
Methods and apparatus for TMAH etching
AssigneeStmicroelectronics Pte Ltd
InventorsYing Yu, Tien Choy Loh, Shian Yeu Kam
Life of this patent
Estimating the term…
Abstract
Methods and apparatus for etching materials using tetramethylammonium hydroxide (TMAH) are described. The methods may involve including an additive when applying the TMAH to the material to be etched. The additive may be a gas, and in some situations may be clean dry air. The clean dry air may be provided with the TMAH to minimize or prevent the formation of hillocks in the etched structure. Apparatus for performing the methods are also described.
Claims12
A method, comprising:
- etching a trench in a crystalline semiconductor material disposed within an etching chamber by:
- introducing tetramethylammonium hydroxide (TMAH) into the etching chamber during an etching period;
- flowing clean dry air (CDA) into the etching chamber during at least part of the etching period;
- mixing the TMAH and CDA together in a supply line coupled to said etching chamber to form an etchant comprising a mixture of the TMAH with the CDA;
- and
- applying said etchant from the supply line to a surface of the crystalline semiconductor material to form said trench.
3 more elements
A method, comprising:
- etching a trench in a crystalline semiconductor material disposed within an etching chamber by:
- introducing tetramethylammonium hydroxide (TMAH) into the etching chamber during an etching period;
- and
- flowing clean dry air (CDA) into the etching chamber during at least part of the etching period;
- and
- combining the CDA with the TMAH in a supply line coupled to the etching chamber to form an etchant consisting essentially of TMAH with the CDA agent as an additive;
- and
- applying said etchant from the supply line to a surface of the crystalline semiconductor material to form said trench.
5 more elements
Dependencies are inferred from the claim text.