Post-metal etch treatment to prevent corrosion
AssigneeLam Research Corporation
InventorsRobert J. O'Donnell, Gregory J. Goldspring
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Abstract
A method of improving the post-etch corrosion resistance of aluminum-containing wafers by performing a two-step post-etch passivation sequence which does not involve a plasma. In the first step the pressure is high, relative to typical passivation procedures, and the wafer temperature is relatively low. In the second step, the pressure is ramped down and the wafer temperature is ramped up. This two-step approach results in a more-efficient removal of chlorine from the wafer, and hence improved corrosion resistance.
Claims14
A post-metal etch corrosion treatment method C1comprising:
- surface saturating the wafer, with no plasma;
- and
- subsequent to the surface saturation, a corrosion cycle quench, where a pressure in the reaction vessel is quickly ramped down, and the wafer temperature is quickly ramped up, with no plasma so that a plasma free environment is provided from the beginning of the surface saturation until the end of the corrosion cycle quench.
A passivation method for passivating HCl on a metal containing layer formed on a wafer, comprising:
- providing a surface saturation at a first pressure and a first wafer temperature, which allows a surface of the wafer to become saturated;
- and
- providing a corrosion cycle quench, subsequent to the surface saturation, wherein the corrosion cycle quench causes the removal of water and HCl from the surface of the wafer and comprises:
- ramping down the pressure to a second pressure below the first pressure;
- ramping up the wafer temperature to a second wafer temperature above the first wafer temperature;
- and
- providing a plasma free environment around the wafer during the surface saturation and the corrosion cycle quench.
Dependencies are inferred from the claim text.