摘要 |
<p>Method of pretreating a semiconductor wafer so that a solution coating of a positive resist of poly(methacrylic anhydride) can be directly applied to the treated surface. A typical semiconductor wafer of silicon is first precoated with a thin layer of poly(t-butyl methacrylate) and then heated to convert the poly(t-butyl methacrylate) to the anhydride. The thickness of this anhydride-precursor layer is less than about 1,000 Angstroms. Next, there is applied to the surface of the precursor layer a solution of the poly(methacrylic anhydride) disolved in, for example, dimethylacetamide, dimethylformamide, or N-methyl-pyrrolidione. Such solvents, which are not capable of adequately wetting the silicon surface directly, are capable of wetting the precursor layer comprising poly(methacrylic anhydride), thus ensuring a uniform deposit of poly(methacrylic anhydride) upon the treated surface of the wafer. After the solution has been applied to the treated wafer, the solvent is removed by evaporation to form a uniform solution-deposited poly(methacrylic anhydride) layer having a thickness which ranges from about 2,000 Angstroms to about 20,000 Angstroms.</p> |