APPARATUS AND METHOD FOR ETCHING SILICON SUBSTRATE HAVING FORMED CIRCUIT PATTERN

摘要

PROBLEM TO BE SOLVED: To provide an apparatus and a method for etching a Si substrate already having a formed circuit pattern whereby the strength of the Si substrate can be raised by removing a microcrack introducing layer from the Si substrate after mechanical-chemical polishing. SOLUTION: Substrates 7 are held back to back with counterposed upper and lower electrodes 6, 3 and a plasma discharge is caused between first and second electrodes under the condition that the product PL of the distance L (m) between the upper and lower electrodes 6, 3 and the pressure P (Pa) of a plasma generating mixed gas contg. O and a fluoric gas to be fed into a process chamber 5 ranges 2.5-15 (Pa.m). Thus it is possible to improve the strength of the Si substrate by efficiently removing a microcrack introducing layer on the back side of the substrate 7.