Methods for etching doped oxides in the manufacture of microfeature devices
First Claim
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1. A method, comprising:
- selectively etching a doped oxide layer on a microelectronic workpiece, wherein the doped oxide layer is adjacent to a nitride layer on the workpiece, and wherein the doped oxide layer is etched with an etchant including DI;
HF and one of the following acids;
HNO3, HCl, H2SO4, or H3PO4,wherein the etchant has a pH below about 2.0 and comprises (a) a selectivity of phosphosilicate glass (PSG) to nitride of greater than 250;
1, and (b) an etch rate through PSG of greater than 9,000 Å
/minute.
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Abstract
Methods for selectively etching doped oxides in the manufacture of microfeature devices are disclosed herein. An embodiment of one such method for etching material on a microfeature workpiece includes providing a microfeature workpiece including a doped oxide layer and a nitride layer adjacent to the doped oxide layer. The method include selectively etching the doped oxide layer with an etchant comprising DI:HF and an acid to provide a pH of the etchant such that the etchant includes (a) a selectivity of phosphosilicate glass (PSG) to nitride of greater than 250:1, and (b) an etch rate through PSG of greater than 9,000 Å/minute.
34 Citations
19 Claims
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1. A method, comprising:
-
selectively etching a doped oxide layer on a microelectronic workpiece, wherein the doped oxide layer is adjacent to a nitride layer on the workpiece, and wherein the doped oxide layer is etched with an etchant including DI;
HF and one of the following acids;
HNO3, HCl, H2SO4, or H3PO4,wherein the etchant has a pH below about 2.0 and comprises (a) a selectivity of phosphosilicate glass (PSG) to nitride of greater than 250;
1, and (b) an etch rate through PSG of greater than 9,000 Å
/minute. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method, comprising:
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depositing a doped oxide layer on a semiconductor substrate; depositing a nitride material, a polysilicon material, and a TiN material on the substrate and adjacent to the doped oxide layer; and removing all or substantially all of the doped oxide layer on the substrate with an etchant comprising DI;
HF;
HNO3, wherein the etchant etches up to and generally not into the nitride, polysilicon, and TiN materials,wherein the etchant has a pH below about 2.0 and comprises (a) a selectivity of phosphosilicate glass (PSG) to nitride of greater than 250;
1, and (b) an etch rate through PSG of greater than 9,000 Å
/minute. - View Dependent Claims (16, 17, 18, 19)
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Specification