InGaP-GaAs Heterojunction Bipolar Transistor Research Articles

Temperature dependence of sensing properties of hydrogen-sensitive extended-base heterojunction bipolar transistors

A planar-type metal-semiconductor-metal (MSM) hydrogen sensor forming on the collector layer was employed as an extended base (EB) of the InGaP-GaAs heterojunction bipolar transistors (HBTs). Then, hydrogen sensing transistors integrated were proposed and studied. After introducing sensing properties of the EB-hydrogen sensor, various sensing current gains defined were addressed for our hydrogen sensing transistor. Instead of the base current, N2 and/or hydrogen-containing gases were used as a parameter while measuring common-emitter characteristics of the hydrogen sensing transistor at various temperatures. Experimental results show that maximum sensing base current gains in 1% H2/N2 is 330 at 25 °C while it is enhanced to 1800 at 50 °C, then to 2300 at 80 °C, and finally to 2800 at 110 °C. In contrast, a peak sensing collector current gain is as high as 1.2 × 105 (4.3 × 104) in 1% (0.01%) at 110 °C. In addition, response times obtained from the sensing diode (base) and collector currents in 0.01% H2/N2 are 485 (490) and 745 s at 25 °C. Together with important features including one power supply and low-power consumption, the proposed hydrogen sensing transistor is very promising for applications in detecting hydrogen.

Design narrow-band frequency amplifier (1.5GHz -1.6GHz) based on InGaP Heterojunction Bipolar Transistor (HBT) and GaAs HBT

The research aims to design a narrow-band frequency drive amplifier (1.5GHz -1.6GHz), which is used to boost the transmitter amplifier's input signal or amplify the GPS, GlONASS signals at the L1 band.
 The Power Amplifier printed circuit board (PCB) prototype was designed using InGaP HBT homogeneous technology transistor and GaAs Heterojunction Bipolar Transistor (HBT) transistor. Two models have been compared; one of the models gave 16dB gain, and the other gave 23dB when using an input power signal (-15dBm). The PCB consumes 2.4W of power and has a physical dimension of 11 x 4 cm.

A low phase noise InGaP–GaAs HBT Colpitts VCO with a high quality differential inductor

A balanced Colpitts voltage controlled oscillator (VCO) topology with its two implementations in a GaAs heterojunction bipolar transistor (HBT) process is introduced in this paper. A detailed analysis of phase noise, originating from the work by Hajimiri and Lee, is given, which depicts a specific outline of the phase noise generation mechanisms in GaAs HBT based harmonic oscillators including LC cross coupled/Colpitts/class C VCOs. In addition, phase noise expressions for HBT based VCOs are derived, compared and act as an optimization tool in oscillator designs. The theoretical analysis of phase noise is authenticated with two balanced Colpitts VCOs with their respective center oscillation frequencies of 850 MHz and 1670 MHz, which are fabricated in a 2 µm GaAs HBT H20HL process. Measurement results show a phase noise of − 139 dBc/Hz at 1 MHz offset from an 850 MHz carrier and a phase noise of − 134 dBc/Hz or less at 1 MHz offset from a 1700 MHz carrier. The output power variation is less than 0.5 dBm over the tuning range. A relatively good match between numerical simulation and measurements is observed.

Comprehensive analysis of GR noise in InGaP–GaAs HBT by physics-based simulation and low frequency characterization

The presence of noise in semi-conductor devices is a major drawback for good quality telecommunications or radar links. It plays an important role on the deterioration of spectral purity in frequency sources and in mixer circuits used in emission and reception in these systems. Thus, the circuit designers must take it into account in their designs by using accurate noise models of transistors. However, these models will be reliable only if the origin of the noise is well-known. The only solution to solve this problem is to have a physics-based simulator including noise simulation, whose results can be compared with noise measurements of the simulated device. This paper presents such a tool, based on a first deterministic simulation with the commercial Technology Computer Aided Design (TCAD) SENTAURUS from SYNOPSYS and whose results are transferred to a home-made tool based on the free SCILAB platform. Thus, this package enables us to simulate the generation---recombination (GR) noise due to traps generated in the device, in this case an InGaP---GaAs heterojunction bipolar transistor (HBT) from UMS foundry. The setup for low frequency (LF) noise characterization available in the lab, allowed us to compare the HBT equivalent current noise sources measured and those simulated with good agreement. This full LF noise comparison of InGaP---GaAs HBT behaviour is the first published to our knowledge and these results confirm a posteriori the pertinency of the LF noise model we developed a few years ago.

Integrated Hydrogen-Sensing Amplifier With GaAs Schottky-Type Diode and InGaP–GaAs Heterojunction Bipolar Transistor

New hydrogen-sensing amplifiers are fabricated by integrating a GaAs Schottky-type hydrogen sensor and an InGaP-GaAs heterojunction bipolar transistor. Sensing collector currents (I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CN</sub> and I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CH</sub> ) reflecting to N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and hydrogen-containing gases are employed as output signals in common-emitter characteristics. Gummel-plot sensing characteristics with testing gases as inputs show a high sensing-collector-current gain (I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CH</sub> /I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CN</sub> ) of > 3000. When operating in standby mode for in situ long-term detection, power consumption is smaller than 0.4 ¿W. Furthermore, the room-temperature response time is 85 s for the integrated hydrogen-sensing amplifier fabricated with a bipolar-type structure.

Room temperature continuous wave operation of a heterojunction bipolar transistor laser

Continuous wave laser operation at 25°C, with simultaneous electrical gain, of an InGaP–GaAs heterojunction bipolar transistor laser, with AlGaAs optical confining layers and an InGaAs recombination quantum well incorporated into the p-type base region, is demonstrated. At laser threshold (IB=40mA, VCB=0, 25°C), the transistor current gain β=ΔIC∕ΔIB in common-emitter operation changes abruptly (2.3→1.2,β&amp;gt;1), with laser modes developing at wavelength λ∼1006nm. Direct three-port modulation of the transistor laser at 3GHz is demonstrated for a device with a 2.2μm emitter width and a 850μm length between cleaved Fabry–Perot facets (which is the performance of an exploratory device and not near the limits).

Low-crosstalk 10-Gb/s flip-chip array module for parallel optical interconnects

A 10-Gb/s optical receiver array with low interchannel crosstalk is realized by exploiting an InGaP-GaAs heterojunction bipolar transistor technology in a three-dimensional multilayer low-temperature cofiring ceramics (LTCC) module. Neutralization feedback circuit with LTCC embedded bus structure is proposed to suppress significant high-frequency crosstalk from on-chip bus and intermetallic capacitance. This module demonstrates 5 dB better suppressed-coupling than a conventional on-chip bus module with 0.8-dB power penalty.

A low-power Ku-band downconverter in InGaP-GaAs HBT technology

We have developed a low-voltage, low-power Ku-band microwave monolithic integrated circuit (MMIC) downconverter using InGaP-GaAs heterojunction bipolar transistor technology. It consists of a preamplifier, a double-balanced mixer, and an L-band wideband intermediate-frequency (IF) amplifier. The downconverter achieves a conversion gain of 31 dB, with a gain flatness within /spl plusmn/ 1 dB, and an output-referred 1-dB compression power (P/sub 1dB,OUT/) of +2.5dBm. This downconverter dissipates 33mA from a 3-V supply. We believe that the operating voltage and power consumption are lower than those of previously published Ku-band MMIC downconverters.

Influences of Surface Sulfur Treatments on the Temperature-Dependent Characteristics of HBTs

The temperature-dependent DC characteristics of InGaP-GaAs heterojunction bipolar transistors with and without sulfur treatment are systematically studied and demonstrated. Due to the use of sulfur passivation, the series resistance of base-emitter junction of studied device can be effectively reduced. In addition, the device with sulfur treatment can be operated under ultra low collector current regimes (I/sub C//spl les/10/sup -11/ A). Experimentally, a long-time sulfur treatment is not appropriate. In this work, the studied device with sulfur treatment for 15 min is a good choice. Furthermore, at measured temperature (298 K-398 K), the studied device with sulfur treatment can reduce collector-emitter offset voltage and the impact of emitter size effect. Moreover, as the temperature is increased, the device with sulfur treatment will exhibit higher DC current gain and more stable temperature-dependent performances. This will extend the application regimes of the studied device in low-power and communication systems.

Use of WN&amp;lt;tex&amp;gt;$_ X$&amp;lt;/tex&amp;gt;as the Diffusion Barrier for Interconnect Copper Metallization of InGaP–GaAs HBTs

Use of WN/sub X/ as the diffusion barrier for interconnect copper metallization of InGaP-GaAs heterojunction bipolar transistors (HBTs) was studied. The WN/sub X/ (40 nm) and Cu (400 nm) films were deposited sequentially on the InGaP-GaAs HBT wafers as the diffusion barrier and interconnect metallization layer, respectively, using the sputtering method. As judged from the data of scanning electron microscopy, X-ray diffraction, Auger electron spectroscopy, and sheet resistance, the Cu--WN/sub X/--SiN and Cu--WN/sub X/--Au structures were very stable up to 550/spl deg/C and 400/spl deg/C annealing, respectively. Current accelerated stress test was conducted on the Cu--WN/sub X/ metallized HBTs with V/sub CE/=2 V, J/sub C/=140 kA/cm/sup 2/ and stressed for 55 h, the current gain (/spl beta/) of these HBTs showed no degradation and was still higher than 100 after the stress test. The Cu--WN/sub X/ metallized HBTs were also thermally annealed at 250/spl deg/C for 25 h and showed no degradation in the device characteristics after the annealing. For comparison, HBTs with Au interconnect metallization were also processed, and these two kinds of devices showed similar characteristics after the stress tests. From these results, it is demonstrated that WN/sub X/ is a good diffusion barrier for the interconnection copper metallization of GaAs HBTs.

&amp;lt;tex&amp;gt;$Ku$&amp;lt;/tex&amp;gt;-Band InGaP–GaAs HBT MMIC VCOs With Balanced and Differential Topologies

Balanced and differential voltage controlled oscillators (VCOs) are investigated with analytic noise models. Fully integrated VCOs in Ku-band are implemented on an InGaP-GaAs heterojunction bipolar transistor technology. The balanced VCO has higher output power and lower phase-noise performance, while drawing lower current than the differential VCO. This coincides with the analytical expectation. The shot noise of collector current contributes less to the phase noise in the balanced VCO (B-VCO) than in the differential VCO. The B-VCO shows 2-3 dB lower phase-noise performances of 90.5, -113.8dBc/Hz at the offset frequencies 100 kHz, and 1-MHz offset at 13.5 GHz than the differential VCO, and figures of merit of 180.7 and -177.6dBc/Hz are achieved, respectively.

An InGaP-GaAs HBT MMIC smart power amplifier for W-CDMA mobile handsets

We demonstrate a new linearized monolithic microwave integrated circuit smart power amplifier of extraordinary high power-added efficiency (PAE), especially at the most probable transmission power of wide-band code-division multiple-access handsets. A PAE of 21% at 16 dBm of output power, which is the maximum bound of the most probable transmission power in IS-95 systems, was obtained, as well as 40% at 28 dBm, the required maximum output power, with a single-chip MMIC power amplifier. The power amplifier has been devised with two InGaP-GaAs heterojunction bipolar transistor amplifying chains parallel connected, each chain being optimized for a different P/sub 1dB/ (1-dB compression point) value: one for 16 dBm for the low-power mode, targeting the most probable transmission power, and the other for 28 dBm for the high-power mode. The high-power mode operation shows 40% of PAE and -30 dBc of adjacent channel leakage power ratio (ACLR) at the maximum output power of 28 dBm. The low-power mode operation exhibits -34 dBc of ACLR at 16 dBm with 14 mA of a quiescent current. This amplifier improves power usage efficiency and, consequently, the battery lifetime of the handset by a factor of three.

A 1-17-GHz InGaP-GaAs HBT MMIC analog multiplier and mixer with broad-band input-matching networks

An InGaP-GaAs heterojunction bipolar transistor (HBT) analog multiplier/mixer monolithic microwave integrated circuit (MMIC) is developed that adopts a Gilbert-cell multiplier with broad-band input-matching networks to widen the bandwidth up to 17 GHz. This MMIC was fabricated using a commercially available 6-in InGaP-GaAs HBT MMIC process. It achieved a measured sensitivity of above 1100 V/W for an analog multiplier and a conversion gain of better than 9 dB for a mixer. It also demonstrated a lower corner frequency and noise than that of an InP HBT analog multiplier. The measured low-frequency noise was 10 nV/sqrt(Hz), which is about half of that of an InP HBT analog multiplier with a similar architecture. The corner frequency of the low-frequency noise was roughly estimated to be 15 kHz. The measured performance of this MMIC chip with gain-bandwidth-product (GBP) of 47 GHz rivals that of the reported GaAs-based analog multipliers and mixers. The high GBP result achieved by this chip is attributed to the HBT device performance and the broad-band input-matching network.

An analysis of the anomalous dip in scattering parameter S/sub 22/ of InGaP-GaAs heterojunction bipolar transistors (HBTs)

The kink phenomenon in scattering parameter S/sub 22/ of InGaP-GaAs heterojunction bipolar transistors (HBTs) was explained quantitatively for the first time. Our results show that the output impedance of InGaP-GaAs HBTs can be represented by a simple series resistance-capacitance (R-C) circuit at low frequencies and a simple parallel R-C circuit at high frequencies very accurately because of the high output resistance of HBTs. The behavior of S/sub 22/ of HBTs is in contrast with that of field effect transistors (FETs), where the smaller drain-source output resistance R/sub ds/ obscures the ambivalent characteristics.

Analysis, design, and optimization of InGaP-GaAs HBT matched-impedance wide-band amplifiers with multiple feedback loops

The realization of matched impedance wide-band amplifiers fabricated by InGaP-GaAs heterojunction bipolar transistor (HBT) process is reported. The technique of multiple feedback loops was used to achieve terminal impedance matching and wide bandwidth simultaneously. The experimental results showed that a small signal gain of 16 dB and a 3-dB bandwidth of 11.6 GHz with in-band input/output return loss less than -10 dB were obtained. These values agreed well with those predicted from the analytic expressions that we derived for voltage gain, transimpedance gain, bandwidth, and input and output impedances. A general method for the determination of frequency responses of input/output return losses (or S/sub 11/, S/sub 22/) from the poles of voltage gain was proposed. The intrinsic overdamped characteristic of this amplifier was proved and emitter capacitive peaking was used to remedy this problem. The tradeoff between the input impedance matching and bandwidth was also found.

Recent progress in the multi-wafer CBE system

Recent progress in the multi-wafer CBE system has demonstrated the potential capability of producing the state-of-the-art compound semiconductor devices with excellent uniformity and reproducibility. The Al compositional uniformity of three 4 inch wafers grown at the same time is 0.2136 ± 0.0014 (standard deviation). The uniformity in thickness, composition, carrier concentration for three 3 inch wafers is within ±1.8%, ±0.003 (Ga in InGaP), and ±2.2%, respectively. The temperature variation across a 3 inch GaAs wafer is ±0.9°C. The extreme abruptness of composition and the doping profiles using gaseous dopant sources are another remarkable advantage of this growth system. The extremely low surface defect density of 2.8 cm −2 for GaAs is routinely obtained. The InGaP GaAs heterojunction bipolar transistor (HBT) with high current gain and superior high-frequency characteristics of excellent uniformity is successfully fabricated. These remarkable results are ascribed to the unique and superior design of the overall growth system: i.e. the novel metalorganic gas cells with the tilted aperture without any diffuser, the improved In-free substrate holder, the completely shut-off shutters, and the gas handling system.

Effect of collector design on the d.c. characteristics of [formula omitted] heterojunction bipolar transistors

InGaP GaAs heterojunction bipolar transistors with various collector structures are compared. The dependence of d.c. device characteristics on the thickness of the n − GaAs spacer in the collector of composite collector devices is presented. Results indicate that the spacer thickness significantly affects the performance of the transistor. An n + doping spike on the InGaP side of the collector heterojunction is included in the collector design of the composite collector devices. Standard single-heterojunction d.c. results are compared to abrupt double- and composite collector heterojunction devices. Optimization of the spacer thickness, in conjunction with the n + doping spike, eliminates most of the detrimental effects associated with a double-heterojunction device while retaining the beneficial properties of a wide-gap collector. As expected, the composite collector structure produces devices with higher breakdown voltages and lower offset voltages than single heterojunction devices. In addition, optimizing the spacer thickness can reduce the collector current saturation voltage of the composite collector device below that of a single-heterojunction device. These characteristics make composite collector heterojunction bipolar transistors ideal candidates for high power microwave device applications.