Patent ID: 6096661
Filing Date: 2000-08-01
Classification: C23C,H01L

Abstract:
A method for depositing silicon dioxide on a substrate at very low temperature using plasma enhanced chemical vapor deposition, the method including the steps of:setting a temperature, in a silicon dioxide deposition chamber, to be about 170.degree. C. or less;flowing silane gas into the silicon dioxide deposition chamber with a flow rate in a range of from about 50 sccm (standard cubic cm per minute) to about 110 sccm (standard cubic in per minute);flowing nitrogen gas (N.sub.2) into the silicon dioxide deposition chamber with a flow rate in a range of from about 500 sccm (standard cubic cm per minute) to about 3000 sccm (standard cubic cm per minute);flowing nitrous oxide gas (N.sub.2 O) into the silicon dioxide deposition chamber with a flow rate in a range of from about 5000 sccm (standard cubic cm per minute) to about 9000 sccm (standard cubic cm per minute);using a predetermined volume for the silicon dioxide deposition chamber such that pressure within the silicon dioxide deposition chamber is in a range of from about 0.5 torr to about 1.3 torr;placing the substrate inside the silicon dioxide deposition chamber for a soak time period in a range of from about 30 seconds to about 40 seconds;applying a high frequency RF signal on a showerhead within the silicon dioxide deposition chamber, wherein the high frequency RF signal has a power in a range of from about 200 Watts to about 600 Watts; andapplying a low frequency RF signal on a heating block for holding the substrate within the silicon dioxide deposition chamber, wherein the low frequency RF signal has a power in a range of from about 150 Watts to about 400 Watts,wherein silicon dioxide is deposited onto the substrate when said high frequency RF signal is applied on said showerhead and when said low frequency RF signal is applied on said heating block holding the substrate,and wherein said deposition of said silicon dioxide is onto a layer of photolithography material on said substrate, and wherein said deposition of said silicon dioxide at temperature of about 170.degree. C. or less preserves the integrity of said layer of photolithography material.