Pei-Hsin Tsien

An improved nonuniformity correction algorithm for infrared focal plane arrays which is easy to implement

An improved nonuniformity correction algorithm is presented which is suitable for infrared focal plane arrays with a nonlinearity of the photoresponse characteristic. Compared to older algorithms, it is simpler, faster and easier to implement by software or hardware. At the same time, it is shown that the correction precision and the correction effect of the new algorithm are substantially the same as that of the old one through theoretical analysis and comparisons of simulation results.

Emitter-ballasting-resistor-free SiGe microwave power heterojunction bipolar transistor

The emitter ballasting resistor is used to equalize the current distribution between the emitter stripes in power transistor, but it will degrade the output power, power gain, and power added efficiency. Experimental results indicate that the current gain of uniform-base SiGe heterojunction bipolar transistors (HBTs) decreases with the increase of the temperature above 160 K, so the current distribution is equalized by itself to some extent. Therefore, the microwave power SiGe HBTs without emitter ballasting resistor were fabricated for the first time, and the continuous output power of 5 W and power added efficiency of 63% were obtained under Class C operation at a frequency of 900 MHz. Hence, the emitter current density of the SiGe HBTs with emitter width of 6 /spl mu/m is 0.79 A/cm.

Formation of TiSi/sub 2/ and shallow junction by As/sup +/ ion-beam mixing and infrared rapid heat treatment

A technique for forming shallow junctions with low-resistance silicide contacts developed for the use in VLSI with scaled MOSFETs is discussed. The salicide (self-aligned silicide) MOSFET gate and source-drain features self-aligned refractory metal silicide and are isolated from one another even without any insulating spacer on the gate sides. A critical step in such a MOSFET fabrication process is the ion implantation through metal silicidation technique, which includes As/sup +/ ion-beam-induced titanium-silicon interface mixing and infrared rapid heat treatment to form simultaneously the n/sup +/-p junction and a high-quality TiN covered TiSi/sub 2/ contact layer. >

Defect-free silicon film on SiO/sub 2/ formed by zone melting recrystallization with high scanning speed

The recrystallization of polysilicon films on silicon dioxide at high scanning speed, in the range of 5 approximately=15 mm/s, with an RF-induced graphite strip heater system is discussed. The films are in

Composition determination of Si/Si1−xGex/Si by photoreflectance spectroscopy

UHVCVD-grown Si/Si1−xGex/Si heterostructure is investigated by photoreflectance spectroscopy (PR). The principle of PR in determining Ge content of a Si1−xGex epilayer is thoroughly described. The unambiguous E1 transition energy in the Si1−xGex epilayer is very useful to determine Ge content during PR analysis. R&R study with 10 repeats at the same point indicates that the measurements of PR are reproducible. These results demonstrate that PR is very promising for analysis of Si1−xGex epilayer characterization with constant Ge content.

Relaxation Behavior of Metastable As and P Concentrations in Si After Pulsed and CW Laser Annealing

Metastable solid solutions of arsenic and phosphorus atoms were created by high-dose ion implantation in silicon, followed by annealing either with pulsed (Nd:YAG) or CW (CO 2 ;) laser irradiation. The relaxation of these supersaturated layers was investigated by thermal post-treatment at temperatures between 600 and 1000°C. By measuring the time dependence of the sheet carrier concentration, the time constant and the activation energies for the relaxation of the electrically-active As and P atoms were investigated. In addition, the equilibrium carrier concentrations at different temperatures were obtained by Halleffect measurements in connection with a layer-removal technique.

Growth of SiGe film by using a single-wafer rapid thermal processing UHV/CVD system

Ultra-high-vacuum chemical vapor deposition (UHV/CVD) system displays excellent performance for the growth of high-quality SiGe film. Investigations have shown that have shown that SiGe film grown by this system has high quality. A 10-finger SiGe hetero-junction bipolar transistor (HBT) device displayed good electrical performance. The current gain was about 500, and the fT was 5.4 GHz with fmax 7.5 GHz under VCB=3 V, IC=10 mA.

High-quality n-Si/i-p+-i SiGe/n-Si structure grown by ultra high vacuum chemical molecular epitaxy

The n-Si/i-p+-i SiGe/n-Si structure was grown by ultra high vacuum chemical molecular epitaxy, and analysed by high resolution X-ray diffraction, cross-sectional transmission electron microscopy, and secondary ion mass spectroscopy. A high-quality SiGe base layer with an abrupt interface to the Si was obtained. No defects were observed in the n-Si/i-p+-i SiGe/n-Si structure. Both the Ge and boron atoms are uniformly distributed in the p+-SiGe layer, and the changes of profile of both boron and Ge atoms are abrupt from the n-Si to the SiGe layer. A high-performance microwave power SiGe heterojunction bipolar transistor (HBT) was made from the n-Si/i-p+-i SiGe/n-Si structure. Therefore, device-quality n-Si/i-p+-i SiGe/n-Si structures can be grown by ultra high vacuum chemical molecular epitaxy.

Improvement on the performance of P+-GexSi1-x/p-Si heterojunction internal photoemission infrared detectors at 77 K

By using a stacked structure, adding an SiO2 dielectric cavity and an Al mirror, and evaporating a SiO anti-reflecting layer on the back of the substrate, the peak detectivity D-(5.5,D-1000,D-1)* of an unbiased P+-GexSi1-x/p-Si heterojunction internal photoemission (HIP) infrared detector at 77 K has been improved to 1.1 X 10(10) cm Hz(1/2)/W, with a peak quantum efficiency of similar to 2.8% and a photoresponse range of 2-8 mu m. Its D-p* is of the same order of magnitude as that of the PtSi infrared detectors being used in practice. In addition, an improved electrode structure is used in order to improve the performance and reliability of the device

Effects of neutron irradiation on SiGe HBT and Si BJT devices

The change of electrical performance of SiGc HBT and Si BJT is studied after irradiation with 1.3×1013 and 1.0×1014 reactor fast neutrons cm−2. Ic and β decrease, while Ib increases generally with an increasing neutron irradiation fluence for SiGe HBT. For Si BJT, Ic increases at low Vbe bias, decreases at high Vbe bias; Ib increases; and β decreases much more than a SiGe HBT at the same fluence. It is shown that a SiGe HBT has much better anti-radiation performance than a Si BJT. The mechanism of performance changes induced by irradiation is discussed.