Masamichi Tanabe

A 0.2-/spl mu/m 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

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.

130-GHz f/sub T/ SiGe HBT technology

A real emitter/base heterojunction was formed with the optimization of the vertical profile of the transistor, and good crystallinity of SiGe was achieved by using a UHV/CVD system with high-pressure H/sub 2/ precleaning of the substrate. As a result, a record cutoff frequency up to 130 GHz and the current gain up to 29,000 were obtained with a graded and uniform Ge profiles, respectively.

A 3-10 GHz bandwidth low-noise and low-power amplifier for full-band UWB communications in 0.25- /spl mu/m SiGe BiCMOS technology

We have developed a SiGe HBT low-noise amplifier (LNA) for ultra-wideband (UWB) systems. We reduced the noise figure (NF) over the frequency range from 3.1 to 10.6 GHz (the FCC-specified UWB range) by using a novel LNA structure with an inductor-terminated, common-base input stage in front of a resistive-feedback amplifier. The circuit topology simultaneously enables increased gain for the input stage and wideband noise matching. On-chip measurement using microwave probes has shown that the LNA - fabricated using commercially available 0.25- /spl mu/m SOI SiGe BiCMOS technology - provides a wide 3-dB bandwidth of 14.5 GHz, an S21 of 22 dB, and a low noise figure ranging from 2.7 dB to 3.9 dB, along with low power consumption of 13.2 mW. Deviation of the S21 group delay is kept within 25 ps to ensure faithful signal amplification. The LNA occupies a chip area of 0.49 mm/sup 2/.

A selective-epitaxial SiGe HBT with SMI electrodes featuring 9.3-ps ECL-gate delay

A selective-epitaxial SiGe base heterojunction bipolar transistor (HBT) with self-aligned stacked metal/IDP (SMI) electrodes is proposed. The SiGe-base structure, self-aligned to the 0.1-/spl mu/m-wide emitter, effectively reduces collector capacitance and SMI electrodes provide low parasitic resistances. A BPSG/SiO/sub 2/-refilled trench was introduced to reduce the substrate capacitance. A 9.3-ps delay time in a differential ECL ring oscillator was achieved.

45 GHz transimpedance 32 dB limiting amplifier and 40 Gb/s 1:4 high-sensitivity demultiplexer with decision circuit using SiGe HBTs for 40 Gb/s optical receiver

A preamplifier with 45 GHz bandwidth and 50.2 dB/spl Omega/ transimpedance gain, a limiting amplifier with 32 dB gain and 49 GHz bandwidth, and a 40 Gb/s 1:4 high-sensitivity demultiplexer (HS-DEMUX) combined with a decision circuit are for use in a 40 Gb/s optical receiver. The bandwidth in the preamplifier and the maximum gain at 40 GHz in the limiting amplifier are the best reported for any semiconductor technology. The 1:4 HS-DEMUX uses bit-rotation for byte-synchronization.

82 GHz dynamic frequency divider in 5.5 ps ECL SiGe HBTs

A dynamic frequency divider with 82.4 GHz maximum operating frequency, the fastest reported in any semiconductor technology, and a static frequency divider with 60 GHz maximum operating frequency, the fastest reported in Si, are intended for future millimeter-wave systems. These frequency dividers are fabricated in self-aligned selective-epitaxial-growth (SEG) SiGe heterojunction bipolar transistors (HBTs). These SiGe HBTs provide a 122 GHz cutoff frequency, a 163 GHz maximum oscillation frequency, and 5.5 ps ECL gate delay, the fastest reported in Si.

Ultra-low-power and high-speed SiGe base bipolar transistors for wireless telecommunication systems

Ultra-low-power and high-speed SiGe base bipolar transistors that can be used in RF sections of multi-GHz telecommunication systems have been developed. The SiGe base and a poly-Si/SiGe base-contact were formed by selective growth in a self-aligned manner. The transistors have a very small base-collector capacitance (below 1 fF for an emitter area of 0.2/spl times/0.7 /spl mu/m) and exhibit a high maximum oscillation frequency (30-70 GHz) at low current (5-100 /spl mu/A). The power-delay product of an ECL ring oscillator is only 5.1 fJ/gate for a 250-mV voltage swing. The maximum toggle frequency of a one-eighth static divider is 4.7 GHz at a switching current of 68 /spl mu/A/FF.

40 Gb/s analog IC chipset for optical receiver using SiGe HBTs

A preamplifier with 35 GHz bandwidth and 48.7 dB/spl Omega/ transimpedance gain, an automatic-gain-control (AGC) amplifier core with 31 GHz bandwidth, and a 40 Gb/s decision circuit are presented for future optical-transmission systems at a data rate of 40 Gb/s in global communication systems. A self-aligned selective-epitaxial SiGe-base heterojunction bipolar transistor is used to implement these circuits. This analog IC chipset meets the requirements for a 40 Gb/s optical receiver.

A 0.2-/spl mu/m self-aligned SiGe HBT featuring 107-GHz f/sub max/ and 6.7-ps ECL

A 0.2-/spl mu/m self-aligned selective-epitaxial-growth (SEG) SiGe heterojunction bipolar transistor (HBT), with shallow-trench and dual-deep-trench isolations and Ti-salicide electrodes, was developed. The process, except the SEG, is almost completely compatible with well-established BiCMOS technology. The SiGe HBTs exhibited a peak maximum oscillation frequency of 107 GHz and an ECL gate delay time of 6.7 ps. Four-level interconnects, including MIM-capacitors and high-Q inductors, were formed by chemical mechanical polishing.

Optimization of characteristics related to the emitter-base junction in self-aligned SEG SiGe HBTs and their application in 72-GHz-static/92-GHz-dynamic frequency dividers

Characteristics related to the emitter-base junction of self-aligned selective-epitaxial-growth SiGe heterojunction bipolar transistors (HBTs) were optimized for use with a highly-doped base. The thickness of the Si-cap layer affected both the emitter-base junction concentration and space-charge width, so the dc and ac characteristics of the SiGe HBTs were in turn dependent on this thickness. With a 4/spl times/10/sup 19/-cm/sup -3/ boron-doped base, a 131-GHz cutoff frequency and ECL gate-delay time of 5.4 ps were achieved for the optimized SiGe HBTs. A static frequency divider with a maximum operating frequency of 72.2 GHz and a dynamic frequency divider with a maximum operating frequency of 92.4 GHz were developed for optical-fiber link and millimeter-wave communication systems of the future.