Abstract: A circuit for protecting an input MOS FET (Q1) from electrostatic discharge pulses includes a plurality of diodes (D112a through D112f) coupled to the bonding pad (102) of an integrated circuit via a plurality of resistors (R110a through R110f). The resistors prevent excessive current from flowing through and hence damaging any of the diodes. The diodes possess a unique shape which maximizes the perimeter to surface area ratio and therefore permits more efficient energy dissipation along the periphery of the diodes. The diodes are adapted to break down in response to an excessive voltage at the bonding pad and therefor protect the gate structure of the input transistor. Also included in the circuit is a protective bipolar transistor (Q2) having a collector coupled to the bonding pad, an emitter coupled to ground and a base resistively coupled to ground.

Abstract: A metal-semiconductor-metal photodiode comprises a semiconductor layer and a cathode electrode and an anode electrode which are formed on the semiconductor layer and are made of such mutually different electrode materials that the cathode electrode has a Schottky barrier height .phi..sub.bn from a conduction band satisfying .phi..sub.bn >Eg/2 and the anode electrode has a Schottky barrier height .phi..sub.bp from a valence band satisfying .phi..sub.bp >Eg/2, where Eg denotes the energy band gap.

Abstract: Implantation of oxygen or nitrogen in polysilicon layers to a dose above about 10.sup.15 ions/cm.sup.2 retards rapid grain boundary migration of conventional dopants such as B, P, As, Sb, and the like during dopant activation. Pre-annealing of the poly films to increase the grain size also decreases rapid grain boundary migration. The effects can be combined by first pre-annealing and then implanting oxygen or nitrogen before introducing the dopant. It is desirable to anneal the oxygen implant before introducing the dopant to allow for oxygen diffusion to the grain surfaces where it precipitates and blocks the grain boundaries. Vertical and lateral migration of the dopants can be inhibited by placing the implanted oxygen or nitrogen between the dopant and the location desired to be kept comparatively free of dopants. When very high dopant activation temperatures are used the blocking effect of the oxygen on the grain boundaries is overwhelmed by dopant diffusion through the grains.

Abstract: This invention is directed to a three-terminal semiconductor device which acts as a differential light detector. It is based on the operation of two reverse biased PIN photodetectors where one receives light through its P-doped surface and the other through its N-doped surface. The device is configured to be compatible with applications in integrated optics and with fiber optics. In principle of operation the invention relies on the production and collection of electrons from the detection of a first light intensity and the production and collection of holes from the detection of the intensity of a second light. This is done in a connected or integrated semiconductor which allows the recombination of electrons and holes. The excess number of electrons or holes, depending upon which light is received with the greatest intensity, is extracted from the recombination region and is the basis for the output signal.