Uniform and high performance of monolithically integrated1×12 array of planar GaInAs photodiodes

In this article, we describe the fabrication of a monolithically integrated 1×12 array of GaInAs/InP planar photodiodes, which has highly uniform characteristics in dark current, capacitance and crosstalk capacitance, quantum efficiency, and the frequency bandwidth at 3-dB reduction with a deviation of ±1%. Besides, each diode on the array exhibits an extremely low dark current of 75 pA, a low capacitance of ~2.3 pF and a crosstalk capacitance between adjacent diodes of ~0.36 pF, a high quantum efficiency of 95% at 1.3 μm and 89% at 1.53 μm, the 3-dB frequency of >2 GHz, and a small 1/f noise component over a wide operating voltage range. Also, the diode on the array has a negligible degradation after the burn-in test of -20 V, 200°C, and 20 h     

High-Q GaAs varactor diodes

A double epitaxial gallium arsenide tuning diode has been developed for TV varactor tuners. The capacitance variation ratio is 6.0 and is large enough to cover the UHF TV broadcasting band. Diode series resistance is 0.18 Ω (Q = 200) at 470 MHz, and at a capacitance of 9 pF. This resistance is 4.4 times smaller than Si diodes in its mean value. Contribution of each resistance component to the total diode resistance was studied. The result shows that package loss is 0.11 Ω, RF skin-effect resistance is 0.05 Ω, and the undepleted epitaxial layer resistance is 0.048 Ω. Therefore, a diode with a 0.075-Ω (Q = 480) series resistance at 470 MHz could be developed, if package loss and RF skin-effect resistance are improved.     

A novel beam lead GaAs Schottky-barrier diode fabricated by using thick polyimide film

A novel beam lead GaAs Schottky-barrier mixer diode with high performance has been developed for use in super high frequency (SHF) receiving system. The parasitic capacitance of the diode has been reduced to 0.03 pF by using thick polyimide insulating film formed by improved etching techniques. The series resistance has been lowered to 0.5 Ω by a liquid-phase double epitaxial method of growing an n-n⁺⁺active layer on an n⁺wafer. The total diode capacitance at zero bias has been lowered to 0.15 pF using a 10-µm junction diameter. An n factor of less than 1.10 was obtained. The calculated cutoff frequency including parasitic capacitance exceeds 2000 GHz. Several reliability tests including temperature cycling in high humidity show good results. In an SHF downconverter consisting of a waveguide which contains a planar circuit, the diode was attached to the planar circuit by means of an intermediate plate, despite the small diode dimensions of 0.75 mm by 0.22 mm. An overall noise figure (NF) as low as 4.3 dB, and conversion loss as low as 3.0 dB were achieved at 12 GHz (IF range of 290-470 MHz and IF amplifier NF of 1.5 dB). These values are shown to be satisfactory for application to a low-noise receiving system for satellite TV broadcasting.     

Characterization of In0.53Ga0.47As photodiodes exhibiting low dark current and low junction capacitance

The preparation and properties of grown p-n homojunction In0.53Ga0.47As photodiodes for operation in the1-1.7 mum wavelength range are described. At a reverse bias of 20 V, these diodes exhibit generation-recombination limited dark current as low as2 times 10^{-9}A, junction capacitance of 0.3 pF, and pulse response corresponding to a circuit-limited rise time of 60 ps and diffusion-limited full width (FWHM) of 140 ps.     

A p-Ge1-xCx/n-Si heterojunction diode grownby molecular beam epitaxy

We report on the fabrication and characterization of the first p-n diode made from a heterojunction of epitaxial p-type Ge_0.998C _0.002 on an n-type Si substrate. Epitaxial Ge_0.998C_0.002 was grown on a (100) Si substrate by solid source molecular beam epitaxy. The p-GeC/n-Si junction exhibits diode rectification. The I-V characteristics of the p-GeC/n-Si diode indicate a reasonable reverse saturation current of 89 pA/μm² at -1 V and a high reverse breakdown voltage in excess of -40 V. Photoresponse from the Ge_0.998C_0.002 p-n diode was observed from 1.3-μm laser excitation resulting in an external quantum efficiency of 1.4%     

Performance and reliability of an improved high-temperature GaAs Schottky junction and native-oxide passivation

We have developed a reliable, high-performance, batch-processed, GaAs tantalum Schottky diode (with a gold overlayer) and native-oxide passivated junction¹in a quasi-planar configuration, Varactors and mixers have been fabricated with near-ideal characteristics and state-of-the-art performance. Typically, they exhibit, at 0 V, a junction capacitance near 0.1 pF and a cutoff frequency in excess of 700 GHz when measured at 55 GHz. In a paramp application pumped at 101 GHz, and a signal frequency of 35 GHz, we have obtained a noise figure of 3.5 dB, a gain of 17 dB, and a bandwidth of 600 MHz. When used as frequency doublers (50-100 GHz) and triplers (35-105 GHz), we have realized better than 25-percent efficiency. As mixers, atXband, we achieved a single sideband noise figure of 6 dB and the diodes are typically able to sustain short pulse energy (1.5 × 10^-9s) of up to 4.5 ergs with no performance degradation. Reliability tests results to date indicate a MTBF of better than 10⁸h at 100°C and greater than 10⁵h at 200°C. In a commercial application of paramps (3.7-4.2 GHz), these diodes have successfully completed 2.5 million operational varactor hours with no performance degradation.     

用于高功率密度功率因素校正的新一代600V砷化镓肖特基二极管

在200W连续导通模式功率因数校正（PFC）系统中，新一代600V砷化镓（GaAs）肖特基二极管与硅和碳化硅（SiC）二级管比较，砷化镓、碳化硅在PFC系统中的损耗减少高达25％。由于砷化镓有较低的结电容，砷化镓相对碳化硅高的通态损耗被较低的MOSFET损耗弥补了。和碳化硅技术相比，砷化镓有成本和可靠性优势。对于高频和高密度应用来说，新一代的砷化镓二级管是很有前景的。     

Dependency of the highest harmonic oscillation frequency on junction diameter of IMPATT diodes

The effect of series resistance and junction capacitance on the high-frequency limit of IMPATT diode operation is studied with a Read-type small-signal theory, and is confirmed experimentally. Oscillation frequencies from 30 to 400 GHz have been measured with Si p⁺-n-n⁺abrupt junction diodes with a depletion layer width of 0.2 µm. The highest oscillation frequency increases as the junction diameter is decreased, owing to reduced junction capacitance and increased bias-current density. The highest oscillation frequency observed is 423 GHz, which is obtained in the fifth harmonic mode with a diode of 16-µm junction diameter. Fundamental oscillation frequency is found to depend strongly on dc bias-current density, and to be close to the avalanche frequency of the small-signal theory.     

SiC/Si heterojunction diodes fabricated by self-selective and byblanket rapid thermal chemical vapor deposition

SiC/Si heterojunction diodes have been fabricated by two different rapid thermal chemical vapor deposition (RTCVD) processes: a localized self-selective growth and blanket growth. The self-selective growth of crystalline cubic (β) SiC was obtained by propane carbonization of the Si substrate in regions unprotected by an SiO₂ layer, producing planar diodes. Mesa diodes were fabricated using the blanket growth of polycrystalline β-SiC produced by the decomposition of methylsilane (CH₃SiH₃). The SiC/Si heterojunction diodes show good rectifying properties for both device structures. Reverse breakdown voltage of 50 V was obtained with the self-selective SiC/Si diode. The mesa diodes exhibited even higher breakdown voltages (V_br) of 150 V and excellent ideality factors of 1.06 at 25°C. The high V_br and good forward rectifying characteristics indicate that the SiC/Si heterojunction diode represents a promising approach for the fabrication of wide-gap emitter SiC/Si heterojunction bipolar transistors     

On Estimating and Canceling Parasitic Capacitance in Submillimeter-Wave Planar Schottky Diodes

The equivalent circuit model of a submillimeter planar diode is investigated. In particular, the parasitic finger to pad capacitance that shunts the diode junction severely degrades the performance of frequency multiplier. Therefore, precise estimation of its value is crucial to circuit design in the submillimeter wave range. In this letter, a parallel diode structure is analyzed, and symmetry is utilized to remove parasitic elements external to the finger loop. This analytical approach is verified through measurement on a 200 GHz planar diode circuit. To increase the diode junction capacitance modulation ratio, one possible solution is also suggested.      

Formation of TiN/TiSi2/p+-Si/n-Si by rapid thermal annealing (RTA) silicon implanted with boron through titanium

A low temperature method of fabricating conductive (3.5 Ω/ sq.) p⁺/n junction diodes possessing excellentI-Vcharacteristics with reverse-bias leakage less than -3 nA.cm^-2at -5 V is described. Single crystal n-type 〈100〉 Si is implanted with 60 keV¹¹B+through 0.028-µm thick sputtered Ti film. Rapid thermal annealing (RTA) in an N2ambient simultaneously forms a 0.36-µm deep p⁺/n junction and a 0.063-µm thick bilayer of TiN and TiSi2with a resistivity of 22 µΩ.cm. The electrical properties of these diodes are not degraded by annealing for 30 min at 500°C, suggesting that the outer layer of TiN is an effective diffusion barrier between TiSi2and Al.     

Integration of high-Q GaAs varactor diodes and 0.25 μmGaAs MESFET's for multifunction millimeter-wave monolithic circuitapplications

Two technologies are demonstrated whereby high-Q, vertical-structure, abrupt-junction varactor diodes are monolithically integrated with 0.25-μm GaAs MESFETs on semi-insulating GaAs substrates for multifunction millimeter-wave monolithic circuit applications. Diodes with various anode sizes have been realized with measured capacitance swings of >2.1:1 from 0 V to -4 V and series resistances of approximately 1 Ω. Diodes having a zero bias capacitance of 0.35 pF have Q's of >19000 (50 MHz) with -4 V applied to the anode. Under power bias conditions, the MESFETs have a measured gain of >6 dB at 35 GHz with extrapolated values for f _t and f_max of 32 GHz and 78 GHz, respectively. Using these technologies, a monolithic Ka-band voltage controlled oscillator (VCO) containing a varactor diode, a 0.25-μm GaAs MESFET, and the usual MMIC passive components has been built and tested. At around 31 GHz, the circuit has demonstrated 60-mW power output with 300 MHz of tuning bandwidth     

SiC devices: physics and numerical simulation

The important material parameters for 6H silicon carbide (6H-SiC) are extracted from the literature and implemented into the 2-D device simulation programs PISCES and BREAKDOWN and into the 1-D program OSSI Simulations of 6H-SiC p-n junctions show the possibility to operate corresponding devices at temperatures up to 1000 K thanks to their low reverse current densities. Comparison of a 6H-SiC 1200 V p-n^--n⁺ diode with a corresponding silicon (Si) diode shows the higher switching performance of the 6H-SiC diode, while the forward power loss is somewhat higher than in Si due to the higher built-in voltage of the 6H-SiC p-n junction. This disadvantage can be avoided by a 6H-SiC Schottky diode. The on-resistances of Si, 3C-SiC, and 6H-SiC vertical power MOSFET's are compared by analytical calculations. At room temperature, such SiC MOSFET's can operate up to blocking capabilities of 5000 V with an on-resistance below 0.1 Ωcm², while Si MOSFET's are limited to below 500 V. This is checked by calculating the characteristics of a 6H-SiC 1200 V MOSFET with PISCES. In the voltage region below 200 V, Si is superior due to its higher mobility and lower threshold voltage. Electric fields in the order of 4×10⁶ V/cm occur in the gate oxide of the mentioned 6H-SiC MOSFET as well as in a field plate oxide used to passivate its planar junction. To investigate the high frequency performance of SiC devices, a heterobipolartransistor with a 6H-SiC emitter is considered. Base and collector are assumed to be out of 3C-SiC. Frequencies up to 10 GHz with a very high output power are obtained on the basis of analytical considerations     

集成化平面肖特基变容管微波C-V特性物理模型

提出一种集成化平面肖特基变容管微波频段 C- V特性物理模型 ,该模型考虑了由平面结构引起的分布有源层串联电阻、分布结电容、结反向饱和漏电流及侧壁电容对微波频段 C- V特性的影响 ,揭示了集成化平面肖特基变容管 C- V特性对频率的依赖 ,并对变容比作了讨论。模型与实验结果符合得很好     

High sensitivity Si-based backward diodes for zero-biased square-law detection and the effect of post-growth annealing on performance

High-sensitivity Si-based backward diodes were realized that are monolithically integratable with transistor circuitry. Potential applications include large area focal plane arrays. The Si-based backward diodes exhibit a high zero-biased curvature coefficient, /spl gamma/, of 31 V/sup -1/ and a low zero biased junction capacitance, C/sub j/, of 9 fF//spl mu/m/sup 2/, all at room temperature. The predicted low frequency voltage sensitivity, /spl beta//sub V/, for a 50 /spl Omega/ source is 3100 V/W. The high sensitivity, low junction capacitance, and Si/SiGe heterojunction bipolar transistor compatibility of the Si-based backward diodes make them very attractive for zero-bias square-law detector applications.     

A low-power high-speed ion-implanted JFET for InP-based monolithic optoelectronic IC's

We describe a high-performance fully ion-implanted planar InP junction FET fabricated by a shallow (4000-Å) n-channel implant, an n⁺source-drain implant to reduce FET series resistance, and a p-gate implant to form a shallow (2000-Å) abrupt p-n junction, followed by a rapid thermal activation. From FET's with gates 2 µm long, a transconductance of 50 mS/mm and an output impedance of 400 Ω.mm are measured at zero gate bias with a gate capacitance of 1.2 pF/mm. The FET has a threshold voltage of -2.4 V, and a saturated drain current of 60 mA/mm at Vgs= 0 V with negligible drift.     

Current transport characteristics of SiGeC/Si heterojunction diode

The characteristics of heterojunction diodes fabricated from p-type epitaxial Si_0.07Ge_0.91C_0.02 alloy grown by molecular beam epitaxy on n-type Si(100) have been examined by using current-voltage, capacitance-voltage, and Hall effect measurements. The SiGeC/Si heterojunction diode shows good rectification with nearly ideal forward bias behavior and low reverse leakage currents compared to Ge/Si heterojunction diodes. The temperature dependence of the current-voltage behavior indicates that the principle conduction mechanism is by electron injection over a barrier. Reverse breakdown occurs by the avalanche mechanism     

Low-temperature growth of silicon-boron layer as solid diffusionsource for polysilicon contacted p+-n shallow junction

A new material, Si-B, is proposed as a solid diffusion source for fabrication of poly-Si contacted p⁺-n shallow junctions. The junction depth of the Si-B source diode has been measured and compared with that of a BF₂⁺-implanted poly-Si source diode. It was found that the Si-B source diode had a much shallower junction and was less sensitive to thermal budget than the BF₂⁺ source diode. This was attributed to the smaller surface concentration and diffusivity of boron in the silicon in Si-B source diodes. Regarding electrical characteristics of diodes with a junction depth over 500 Å, a forward ideality factor of better than 1.01 over 8 decades and a reverse-current density lower than 0.5 nA/cm² at -5 V were obtained. As the junction depth shrank to 300 Å, the ideality factor and reverse current density of diodes increased slightly to 1.05 and 1.16 nA/cm², respectively. These results demonstrated that a uniform ultrashallow p⁺-n junction can be obtained by using a thin Si-B layer as a diffusion source     

DC characteristics of high-breakdown-voltage p-i-n diodes made by20-MeV Si implantation in InP:Fe

A vertical p-i-n diode is made for the first time in InP:Fe using megaelectronvolt energy ion implantation, A 20-MeV Si implantation and kiloelectronvolt energy Be/P coimplantation are used to obtain a buried n⁺ layer and a shallow p⁺ layer, respectively. The junction area of the device is 2.3×10^-5 cm² and the intrinsic region thickness is ≈3 μm. The device has a high breakdown voltage of 110 V, reverse leakage current of 0.1 mA/cm² at -80 V, off-state capacitance of 2.2 nF/cm² at -20 V, and a DC incremental forward resistance of 4 Ω at 40 mA     

Optically Activated 4H-SiC p-i-n Diodes for High-Power Applications

To realize the benefits of SiC power electronics and optically controlled device technology, we present in this letter optically activated SiC p-i-n diodes for high-temperature and high-power applications. The diodes were fabricated on an n-type 4H-SiC substrate, and measurements show that, when tested at a reverse bias of 1000 V, the diode was switched on by a single UV (337.1 nm) laser pulse with 1.2-mJ optical energy. The FWHM is about 180 ns with a rise time of less than 10 ns and a fall time of about 200 ns. The response time is primarily limited by the RC time constant from the junction capacitance of the diode and the current-limiting resistor in the test circuit. This initial work forms the basis for the further development of high-power high-speed SiC bistable switches.