Mixed frequency high temperature nitride CVD process
AssigneeApplied Materials, Inc.
InventorsSum-Yee Tang, May Yuxiang Wang, Lester A. D'Cruz
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Abstract
A mixed-frequency, high temperature PECVD process is utilized to create a high quality silicon nitride layer having highly conformal properties. Deposition in an ammonia rich ambient at high temperature reduces microloading between dense and isolated features by improving surface mobility of precursors. High quality nitride films formed by the instant process are particularly suited for front-end applications such as the formation of spacer structures and the formation of contact etch stop layers.
Claims16
A method of forming a silicon nitride layer over a substrate disposed in a substrate processing chamber, said method comprising:
- flowing a process gas comprising silane and ammonia into the processing chamber, wherein a flow ratio of said ammonia to said silane in said process gas is at least 10:1;
- and
- forming a plasma from the processing gas by applying both high and low frequency RF power to one or more electrodes in the chamber to deposit said silicon nitride layer.
A method of forming a silicon nitride layer over a substrate disposed in a substrate processing chamber, said method comprising:
- flowing a process gas comprising silane, ammonia and molecular nitrogen into the substrate processing chamber, wherein a flow ratio of said ammonia to said silane in said process gas is at least 10:1;
- heating the substrate to a temperature of at least 500° C.;
- and
- forming a plasma from the processing gas by applying both high and low frequency RF power to one or more electrodes in the chamber to deposit said silicon nitride layer, wherein (i) a power level at which the low frequency power is applied is less than a power level at which the high frequency power is applied, (ii) the low frequency RF power level is less than or equal to 1.0 Watts/in2 and (iii) the high frequency RF power is less than or equal to 2.0 Watts/in2.
Dependencies are inferred from the claim text.