Plasma-assisted etching of single-crystalline silicon and positive photoresist in CF//4 plus N//2 O and CF//4 plus O//2 mixtures was studied as a function of gas compositions in RF-generated plasmas using both a barrel reactor and a parallell-plate reactor. Higher etch rates for silicon and lower etch rates for photoresist are observed in barrel-reactor plasma etching using CF//4 plus N//2 O than are observed for CF//4 plus O//2 mixtures under the same etching conditions. With the aid of ion bombardment, the silicon etch rates are found to be higher under some conditions while lower under others in CF//4 plus N//2 O plasmas. The lack of molecular oxygen and lower concentration of atomic oxygen in the CF//4 plus N//2 O plasma (as contrasted with CF//4 plus O//2 mixtures) is postulated to be a major factor in the etch rate difference. Basic mechanisms responsible for these differences are discussed.
|Number of pages||6|
|Publication status||Published - 1985 Dec 1|
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