The process to decrease the dislocation density in 3-inch Fe-doped InP wafers is described. The crystal growth process is a conventional liquid encapsulated Czochralsky (LEC) but thermal shields have been added in order to decrease the thermal gradient in the growing crystal. The shape of these shields has been optimized with the help of numerical simulations of heat transfer and thermomechanical ...
InAs segments were grown on top of GaAs islands, initially created by droplet epitaxy on silicon substrate. We systematically explored the growth-parameter space for the deposition of InAs, identifying the conditions for the selective growth on GaAs and for purely axial growth. The axial InAs segments were formed with their sidewalls rotated by 30$^{{}^\circ }$ compared to the GaAs base islands un...
The density and light-scattering intensity of oxygen precipitates in CZ silicon crystals are measured by IR light-scattering tomography. The numerical data clarified through the measurements are discussed in relation to the amount of precipitated oxygen. The results obtained here correspond well with the theoretical analysis that oxygen precipitates cause light to scatter. The information obtained...
Te-doped GaSb single crystals are studied by measuring Hall effect, infrared (IR) transmission and photoluminescence (PL) spectra. It is found that the n-type GaSb with IR transmittance can be obtained as high as 60% by the critical control of the Te-doping concentration and electrical compensation. The concentration of the native acceptor-associated defects is apparently low in the Te-doped GaSb ...
To realize high-performance silicon carbide (SiC) power devices, low-resistance ohmic contacts to p-type SiC must be developed. To reduce the ohmic contact resistance, reduction of the barrier height at metal/SiC interfaces or increase in the doping concentration in the SiC substrates is needed. Since the reduction of barrier height is extremely difficult, the increase in the Al doping concentrati...
The development of SiC and GaN power semiconductor market The current state of SiC technology and market, and the development trend in the next few years. The SiC device market is promising. Sales of Schottky barrier diodes have matured and MOSFET shipments are expected to increase significantly over the next three years. According to Yole Développement analysts, SiC is very mature in terms of dio...
X-ray topographic and chemical etching examination of Si:Ge single crystals containing 1.2 at% and 3.0 at% Ge, together with precise lattice parameter measurements, was performed. Diffraction contrasts in the form of concentric `quasi-circles' (striations), probably due to the non-uniform distribution of Ge atoms, were observed in projection topographs. The etching patterns reveale...
We present a non-contact method for the determination of the thermal response time of temperature sensors embedded in wafers. In this method, a flash lamp illuminates a spot on the wafer in periodic pulses; the spot is on the opposite side from the sensor under test. The thermal time constant of the sensor is then obtained from measurement of its temporal response, together with a theoretical mode...