An object is to provide a semiconductor device of which a manufacturing process is not complicated and by which cost can be suppressed, by forming a thin film transistor using an oxide semiconductor film typified by zinc oxide, and a manufacturing method thereof. For the semiconductor device, a gate electrode is formed over a substrate; a gate insulating film is formed covering the gate electrode; an oxide semiconductor film is formed over the gate insulating film; and a first conductive film and a second conductive film are formed over the oxide semiconductor film. The oxide semiconductor film has at least a crystallized region in a channel region.

Semiconductor device, and manufacturing method thereof

The market for driver assistance systems based on millimeter-wave radar sensor technology is gaining momentum. In the near future, the full range of newly introduced car models will be equipped with radar based systems which leads to high volume production with low cost potential. This paper provides background and an overview of the state of the art of millimeter-wave technology for automotive radar applications, including two actual silicon based fully integrated radar chips. Several advanced packaging concepts and antenna systems are presented and discussed in detail. Finally measurement results of the fully integrated radar front ends are shown.

Millimeter-Wave Technology for Automotive Radar Sensors in the 77 GHz Frequency Band

In this paper, we present the receiver and the on-chip antenna sections of a fully integrated 77-GHz four-element phased-array transceiver with on-chip antennas in silicon. The receiver section of the chip includes the complete down-conversion path comprising low-noise amplifier (LNA), frequency synthesizer, phase rotators, combining amplifiers, and on-chip dipole antennas. The signal combining is performed using a novel distributed active combining amplifier at an IF of 26 GHz. In the LO path, the output of the 52-GHz VCO is routed to different elements and can be phase shifted locally by the phase rotators. A silicon lens on the backside is used to reduce the loss due to the surface-wave power of the silicon substrate. Our measurements show a single-element LNA gain of 23 dB and a noise figure of 6.0dB. Each of the four receive paths has a gain of 37 dB and a noise figure of 8.0 dB. Each on-chip antenna has a gain of +2 dBi

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A 77-GHz Phased-Array Transceiver With On-Chip Antennas in Silicon: Receiver and Antennas

This paper introduces floating shields for on-chip transmission lines, inductors, and transformers implemented in production silicon CMOS or BiCMOS technologies. The shield minimizes losses without requiring an explicit on-chip ground connection. Experimental measurements demonstrate Q-factor ranging from 25 to 35 between 15 and 40 GHz for shielded coplanar waveguide fabricated on 10 /spl Omega//spl middot/cm silicon. This is more than a factor of 2 improvement over conventional on-chip transmission lines (e.g., microstrip, CPW). A floating-shielded, differentially driven 7.4-nH inductor demonstrates a peak Q of 32, which is 35% higher than an unshielded example. Similar results are realizable for on-chip transformers. Floating-shielded bond-pads with 15% less parasitic capacitance and over 60% higher shunt equivalent resistance compared to conventional shielded bondpads are also described. Implementation of floating shields is compatible with current and projected design constraints for production deep-submicron silicon technologies without process modifications. Application examples of floating-shielded passives implemented in a 0.18-/spl mu/m SiGe-BiCMOS are presented, including a 21-26-GHz power amplifier with 23-dBm output at 20% PAE (at 22 GHz), and a 17-GHz WLAN image-reject receiver MMIC which dissipates less than 65 mW from a 2-V supply.

Shielded passive devices for silicon-based monolithic microwave and millimeter-wave integrated circuits

A low-noise amplifier, direct-conversion quadrature mixer, power amplifier, and voltage-controlled oscillators have been implemented in a 012-/spl mu/m, 200-GHz f/sub T/290-GHz f/sub MAX/ SiGe bipolar technology for operation at 60 GHz At 615 GHz, the two-stage LNA achieves 45-dB NF, 15-dB gain, consuming 6 mA from 18 V This is the first known demonstration of a silicon LNA at V-band The downconverter consists of a preamplifier, I/Q double-balanced mixers, a frequency tripler, and a quadrature generator, and is again the first known demonstration of silicon active mixers at V-band At 60 GHz, the downconverter gain is 186 dB and the NF is 133 dB, and the circuit consumes 55 mA from 27 V, while the output buffers consume an additional 52 mA The balanced class-AB PA provides 108-dB gain, +112-dBm 1-dB compression point, 43% maximum PAE, and 16-dBm saturated output power Finally, fully differential Colpitts VCOs have been implemented at 22 and 67 GHz The 67-GHz VCO has a phase noise better than -98 dBc/Hz at 1-MHz offset, and provides a 31% tuning range for 8-mA current consumption from a 3-V supply

SiGe bipolar transceiver circuits operating at 60 GHz

This paper reports on SiGe NPN HBTs with unity gain cutoff frequency (f/sub T/) of 207 GHz and an f/sub MAX/ extrapolated from Mason's unilateral gain of 285 GHz. f/sub MAX/ extrapolated from maximum available gain is 194 GHz. Transistors sized 0.12/spl times/2.5 /spl mu/m/sup 2/ have these characteristics at a linear current of 1.0 mA//spl mu/m (8.3 mA//spl mu/m/sup 2/). Smaller transistors (0.12/spl times/0.5 /spl mu/m/sup 2/) have an f/sub T/ of 180 GHz at 800 /spl mu/A current. The devices have a pinched base sheet resistance of 2.5 k/spl Omega//sq. and an open-base breakdown voltage BV/sub CEO/ of 1.7 V. The improved performance is a result of a new self-aligned device structure that minimizes parasitic resistance and capacitance without affecting f/sub T/ at small lateral dimensions.

Self-aligned SiGe NPN transistors with 285 GHz f/sub MAX/ and 207 GHz f/sub T/ in a manufacturable technology

This work reports on SiGe HBTs with f/sub T/ of 350 GHz. This is the highest reported f/sub T/ for any Si-based transistor as well as any bipolar transistor. Associated f/sub max/ is 170 GHz, and BV/sub CEO/ and BV/sub CBO/ are measured to be 1.4 V and 5.0 V, respectively. Also achieved was the simultaneous optimization of f/sub T/ and f/sub max/ resulting in 270 GHz and 260 GHz, with BV/sub CEO/ and BV/sub CBO/ of 1.6 V and 5.5 V, respectively. The dependence of device performance on bias condition and device dimension has been investigated. Considerations regarding the extraction of such high f/sub T/ and f/sub max/ values are also discussed.

SiGe HBTs with cut-off frequency of 350 GHz

The effort to design RF circuits in CMOS is motivated by low cost and significant capacity for on-chip integration. We discuss some of the challenges of implementing RF designs in CMOS, focusing on those introduced by the changing properties of FETs as technology nodes scale and devices shrink. We present methods and tools, using which, designers can ease these challenges and reduce the risk of implementing RF circuits in CMOS.

RFCMOS technology from 0.25/spl mu/m to 65nm: the state of the art

Differential shielding reduces substrate losses and improves the Q-factor of a monolithic inductor on silicon by up to 35% without process modification or a patterned ground shield. Peak Qs of 32 for 4 /spl mu/m thick aluminum and 28 for 2.3 /spl mu/m thick copper metals are demonstrated on 10 /spl Omega/-cm substrates for a 7.7 nH test inductor. The differential shield fulfills all existing metal density requirements, and a compact circuit model is presented that agrees within 8% of measurement.

Differentially-shielded monolithic inductors

Millimeter-wave applications are gaining growing interest in recent times. To meet the challenges for such applications, SiGe HBTs, with simultaneously optimized f/sub T/ and f/sub max/ of >300 GHz, are developed. To the author's knowledge, this is the first report of f/sub T/ and f/sub max/ both exceeding 300 GHz for any Si-based transistor. BV/sub CEO/ and BV/sub CBO/ are 1.6 V and 5.5 V, respectively, with peak current gain of 660. Noise measurement shows F/sub min/ of 0.45 dB and 1.4 dB at 10 GHz and 25 GHz with associate gain of 14 dB and 8 dB, respectively. The results indicate SiGe HBTs are highly suitable for the rapidly expanding millimeter-wave applications.

John E. Florkey

Papers

Self-aligned SiGe NPN transistors with 285 GHz f/sub MAX/ and 207 GHz f/sub T/ in a manufacturable technology

SiGe HBTs with cut-off frequency of 350 GHz

RFCMOS technology from 0.25/spl mu/m to 65nm: the state of the art

Differentially-shielded monolithic inductors

SiGe HBTs for millimeter-wave applications with simultaneously optimized f/sub T/ and f/sub max/ of 300 GHz