Plasma etching method

Abstract

Abstract PURPOSE:To etch the whole surface of a member to be ehuted consisting of silicon having a large area in the uniform quantity of etching by previously determining the consentraion of O2 gas, through which the etching rates of a control section and peripheral section are equalized, and using a mixed gas containing such O2. CONSTITUTION:An silicon wafer 4 coated with a mask composed of Al is position onto a cathode plate, the inside of a tank is evacuated, SF6 gas from an introducing port 7 ans O2 gas form an introducing port 8 are mixed and introduced, and high-frequency power is applied between both pole plates 2, 3 by a power supply 9 to generate plasma in a space 10, thus etching the surface not coated with the mask in the wafer 4. Since S generated by the decomposition of SF6 is oxidized to SO2 by adding O2 gas ans the action of S is prevented at that time, an etching rate is increased, but the quantities of an outer circumferential section and a central section etched alter when the concentratrion of O2 is augmented gradually. The quantity of O2 is controlled to a value at sections close to A and C where dispersion reaches zero, and the wafer is etched. Accordingly, dispersion in the surface is improved remarkably.

Inventors

• 👤 Shigemi Nohara
• 👤 野原　繁美

Bibliographic Details