Study of the packaging effect on blocking voltage of power devices during durability test
We investigated why the blocking voltages of a power device are lowered during a durability test through a device simulation called Technology Computer Aided Design (TCAD) and measurements using the optical beam induced current (OBIC) method. We found that the spread of the depletion layer caused by the bonding wire is what decreased the blocking voltage.
Simulation studies for avalanche induced short-circuit current crowding of MOSFET-Mode IGBT
In this paper, new theory of device failure for MOSFET-Mode IGBTs is presented, for the first time, based on large scale 3D & 2D TCAD simulations. It was found that current filaments appear when the impact ionization in the anode side exceeds a critical avalanche generation rate. The current filamentation occurs because there exist two solutions: state of current filaments and state of uniform current flow beyond the critical avalanche generation rate. Below the critical avalanche rate, there is no state of current filaments, and the device is safe. The calculated results successfully explain the previous experimental results of device failure.
Influence of electric fields on friction electrification between metals and borosilicate glass
Abstract In a cylindrical geometry, electric fields were applied through the entire contact area between the sliding metal and the glass surface. The maximum electric charges developed on the metal were measured and plotted against the applied voltage producing the field. The metals were high-purity nickel and gold. The borosilicate glass was Pyrex, brand 7740. The experiments with nickel, which has a work function greater than that of the glass, were performed in 10 −7 mm Hg vacuum. The experiments with gold, with a work function smaller than that of glass, were carried out in air at atmospheric pressure. The results show that: 1. 1) There is both asymmetry and a reversed slope portion in the charge vs. voltage plot. 2. 2) For a certain range of reversing fields, the electric charge developed on the nickel is always negative and the charge on gold is always positive.