FABRICATION OF INTEGRATED INJECTION LOGIC USING E-BEAM LITHOGRAPHY

Integrated injection logic (I**2L) gates have been fabricated using electron-beam lithography, ion implantation, and advanced I**2L design technology. Minimum line widths of 1. 25 mu m were used to delineate structures five times smaller in area than obtained with conventional design rules. Improved geometry control was achieved by using shallow diffusions and thin epi ( similar 1. 2 mu m). PBS positive resist was used to pattern and etch oxides and TI309 negative resist was used to mask etching of Al/Si and Al/Cu metallizations. Thick PMMA was used as an implant mask for 300-keV p** minus intrinsic base implant. Chip-by-chip alignment of 2. 5 multiplied by 2. 5 mm**2 fields yielded level to level registration accuracy of 0. 2-0. 4 mu m. Using a 25-stage ring oscillator as a test vehicle, gate delays of similar 6 ns at 100 mu A/gate have been measured on 5-collector, n** plus guard ring device structures. These devices also yielded a speed-power product five times lower than that of similar conventionally sized devices.