Electrical characterisation of silicon wafer bonding structures

Metal-insulator-semiconductor-insulator-semiconductor (MISIS) capacitors, fabricated using direct wafer bonding, have been used for the evaluation of the electrical properties of a silicon film (4.1 μim), a buried oxide (42 nm) and its interfaces. After the dry oxidation of the film, the grown oxide has a thickness of 25 nm, and the doping concentration of the film increased by one order of magnitude. The minority carrier generation mechanism was detected. Its activation energy (554 meV), denotes the high-quality of the interfaces. A deep level (315 meV) was found by DLTS. The most probable sources of this trap are mainly the divacancy-phosphorus complexes presented in the Si film. The concentration of dislocations in Si film is very low (< 105 cm-2). Bias-temperature stress (BTS) showed the presence of a low concentration of positive charges (2.2 × 109 cm-2) in the oxide. © 1998 Elsevier Science Ltd. All rights reserved

Potential of HMDS/C3H8 precursor system for the growth of state of the art heteroepitaxial 3C-SiC layers on Si(100)

From a comparative evaluation of hexamethyldisilane (HMDS) and silane-propane (SP) precursor systems, it is shown that HMDS needs a small addition of propane to deposit heteroepitaxial layers of 3C-SiC on Si with superior crystalline properties. In this case, propane compensates for the secondary reactions induced by hydrogen reacting with carbon. Using atmospheric pressure CVD conditions, the new system (HMDS-propane) demonstrates several advantages. It is safer to handle than SP and allows a higher growth rate (up to 7 mum/h at 1350degreesC) without any degradation of the layer morphology. However, lowering the deposition temperature, HMDS has been found more stable than silane. This is opposite to most standard belief but explains why, in this case, a high temperature step (similar to1350degreesC) is always necessary to grow high quality material