A 0.2-μm 180-GHz-f/sub max/ 6.7-ps-ECL SOI/HRS self-aligned SEG SiGe HBT/CMOS technology for microwave and high-speed digital applications

Abstract

A technology for combining 0.2-/spl mu/m self-aligned selective-epitaxial-growth (SEG) SiGe heterojunction bipolar transistors (HBTs) with CMOS transistors and high-quality passive elements has been developed for use in microwave wireless and optical communication systems. The technology has been applied to fabricate devices on a 200-mm SOI wafer based on a high-resistivity substrate (SOI/HRS). The fabrication process is almost completely compatible with the existing 0.2-/spl mu/m bipolar-CMOS process because of the essential similarity of the two processes. SiGe HBTs with shallow-trench isolations (STIs) and deep-trench isolations (DTIs) and Ti-salicide electrodes exhibited high-frequency and high-speed capabilities with an f/sub max/ of 180 GHz and an ECL-gate delay of 6.7 ps, along with good controllability and reliability and high yield. A high-breakdown-voltage HBT that could produce large output swings for the interface circuit was successfully added. CMOS devices (with gate lengths of 0.25 /spl mu/m for nMOS and 0.3 /spl mu/m for pMOS) exhibited excellent subthreshold slopes. Poly-Si resistors with a quasi-layer-by-layer structure had a low temperature coefficient. Varactors were constructed from the collector-base junctions of the SiGe HBTs. MIM capacitors were formed between the first and second metal layers by using plasma SiO/sub 2/ as an insulator. High-Q octagonal spiral inductors were fabricated by using a 3-/spl mu/m thick fourth metal layer.