LSI (Large Scale Integration)/VLSI (Very Large Scale Integration) Ion Implanted GaAs IC Processing.

摘要

This report covers the seventh quarter of a program aimed at fully realizing the potential of GaAs for digital integrated circuits employing depletion mode MESFETs. During this reporting period, growth of low dislocation GaAs crystals by the horizontal Bridgman method is reported. LEC semi-insulating substrate material from a commercial supplier of 3 inch diameter wafers was evaluated finding that three out of four ingots passed the qualification tests. The major process activities centered on the testing of processing equipment before the start of the 3 inch process line. Excellent results in terms of resolution and alignment accuracy of the CENSOR direct-step-on-wafer projection aligner are reported. Resolution better than 1 micron; alignment accuracy, mean + 3 sigma, better than 0.25 micron were measured. Studies have been done in reactive ion etching (using 3 inch process equipment) to optimize differential etch rates. Work on MESFET modeling has continued. (Author)