International Business Machines Corporation

Zeon Corporation

Goh Matsuura

Eric Andrew Joseph

Edmund M Sikorski

Nicholas C M Fuller

Masahiro Nakamura

Bang N To

Pretreatment of an etch chamber for performing a silicon etch process and Bosch process can be effected by running a deposition process employing CHF, or by running an alternating deposition and etch process employing CHFand SF. It has been discovered that the pretreatment of the etch chamber for the silicon etch process can enhance the etch rate of silicon by at least 50% without adverse effect on etch profile during a first each process following the pretreatment, while the etch rate enhancement factor decreases over time. By periodically performing the pretreatment in the etch chamber, the throughput of the etch chamber can be increased without adversely impacting the etch profile of the processed substrates.

Etch rate enhancement for a silicon etch process through etch chamber pretreatment

A hydrofluorocarbon gas is employed as a polymer deposition gas in an anisotropic etch process employing an alternation of an etchant gas and the polymer deposition gas to etch a deep trench in a semiconductor substrate. The hydrofluorocarbon gas can generate a thick carbon-rich and hydrogen-containing polymer on sidewalls of a trench at a thickness on par with the thickness of the polymer on a top surface of the semiconductor substrate. The thick carbon-rich and hydrogen-containing polymer protects sidewalls of a trench, thereby minimizing an undercut below a hard mask without degradation of the overall rate. In some embodiments, an improvement in the overall etch rate can be achieved.

High aspect ratio and reduced undercut trench etch process for a semiconductor substrate

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Hartsdale, NY, United States of America

Goh Matsuura