Abstract: A method for producing an electrical connection between front and rear sides of semiconductor chips in the wafer process.

Abstract: The present invention improves the characteristic of a trench-type vertical MOSFET. When a trench 23 serving as a gate 25 is formed, it is made in a shape of “&ggr;” which is convex toward the inside of the trench. Thus, the surface area of the trench is reduced so that both gate-source capacitance and gate-drain capacitance can be reduced, thereby shortening the switching time of the MOSFET.

Abstract: A test structure for evaluating plasma damage in thin gate oxides is formed with a single polysilicon floating gate EEPROM device on which an antenna structure delivers charge to a floating gate through a tunnel oxide. The floating gate extends beyond the MOSFET channel in one direction, passing over field oxide and terminating in a pad over a thin tunnel oxide window formed over an isolated n+ diffusion. The n+ diffusion is connected to a metal antenna structure which is exposed to a processing plasma. Charge accumulated on the antenna during plasma exposure causes a tunnel current to flow through the tunnel oxide, and charge to accumulate on the floating gate. A second extension of the polysilicon floating gate passes over a second field oxide region and terminates in a pad over a thicker oxide formed on a second isolated n+ diffusion. The second n+ diffusion forms the control gate of the EEPROM and is connected by wiring to a probe pad.