High selectivity nitride to oxide etch process
AssigneeIntegrated Device Technology, Inc.
InventorJang Jen
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Abstract
The process parameters according to which the AMT 8310 RIE plasma etcher operates are altered so as to increase the nitride to oxide selectivity of the AMT 8310 RIE plasma etcher from approximately 3:1 to approximately 5:1, thereby allowing for the fabrication of modern semiconductor devices having oxide films significantly less thick than 325 .ANG.. In this manner, the present invention eliminates the need for an expensive upgrade in etching equipment to realize an increase in nitride to oxide selectivity. The semiconductor device is electrically biased at 100-300 volts, and freon and oxygen have a flow rate ratio of approximately 1:1.
Claims5
A method for etching away portions of a nitride layer without significantly etching away an underlying oxide layer in a semiconductor device, said method comprising the steps of:
- electrically biasing said semiconductor device at between approximately 100 and 300 volts;
- and
- providing Freon and Oxygen gases at first and second flow rates, respectively, wherein said flow rates are approximately 1:1, over a top surface of said nitride layer to remove said nitride layer at a rate of approximately 200 .ANG./min and to remove said oxide layer at a rate of approximately 40 .ANG./min.
Dependencies are inferred from the claim text.