Method of depositing uniform films of Si.sub.x N.sub.y or Si.sub.x O.sub.y in a plasma reactor
AssigneeWestern Electric Company, Inc.
InventorAline Akselrad
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Abstract
A method of depositing a uniform dielectric film on a silicon substrate comprising flowing a plasma comprising an RF-excited mixture of an inert gas such as argon and silane over the substrate to form a film of porous a-Si.sub.x H.sub.y over the surface of the substrate. The flow of plasma is then discontinued and a flow of a nitrogen or oxygen plasma is substituted therefor. The temperature of the substrate is increased to at least 360.degree. C. to diffuse-out hydrogen from the Si.sub.x H.sub.y film on the substrate, each departing hydrogen atom leaving a dangling Si bond behind which combines with the activated oxygen or nitrogen thereby to form the desired dielectric film of formula Si.sub.x N.sub.y or Si.sub.x O.sub.y.
Claims6
A method of depositing a uniform dielectric film on a silicon substrate, comprising the steps of:
- flowing a first plasma comprising an excited mixture of inert gas and a volatile Si compound over said substrate thereby to form a film having porous a-Si.sub.x H.sub.y over the surface of said substrate;
- discontinuing the flow of said first plasma and substituting therefor a flow of a second excited plasma comprising an activated gas selected from the group consisting of oxygen and nitrogen over said substrate;
- and then
- elevating the temperature of said substrate to cause the hydrogen to diffuse-out from said porous a-Si.sub.x H.sub.y film, each departing hydrogen atom leaving behind a dangling Si bond which combines with an excited radical of the activated gas in said second plasma thereby to form said dielectric film of formula Si.sub.x M.sub.y, where M represents either oxygen or nitrogen, depending on the identity of said activated gas.
Dependencies are inferred from the claim text.