In connection with the fabrication of an integrated circuit, a method for simultaneously completing the formation of a contact, an interconnect, a gate and a source or drain is disclosed. An integrated circuit field effect structure wherein a diffused silicon area is connected directly to a polysilicon member by conductive silicon and more specifically the source or drain of one device is directly and continuously connected to the gate of an adjacent device by a conductive silicon member.
In one embodiment, an extremely short channel FET is made by forming a metal layer over a wafer, depositing silicon dioxide over part of the metal layer, oxidizing the exposed metal, controllably etching a portion of the silicon dioxide to expose a small strip of the nonoxidized metal layer, electroplating the exposed metal strip, thereby to form an extremely narrow gate electrode, removing the deposited SiO.sub.2, the metal oxide and the remaining metal layer to leave only the gate electrode, and using the gate electrode as a mask for ion implanting source and drain regions. Since the gate electrode can be made so narrow, the channel region is correspondingly short to give extremely high frequency capabilities. Other embodiments are also described.
In one embodiment, an extremely short channel FET is made by forming a metal layer over a wafer, depositing silicon dioxide over part of the metal layer, oxidizing the exposed metal, controllably etching a portion of the silicon dioxide to expose a small strip of the nonoxidized metal layer, electroplating the exposed metal strip, thereby to form an extremely narrow gate electrode, removing the deposited SiO.sub.2, the metal oxide and the remaining metal layer to leave only the gate electrode, and using the gate electrode as a mask for ion implanting source and drain regions. Since the gate electrode can be made so narrow, the channel region is correspondingly short to give extremely high frequency capabilities. Other embodiments are also described.
In one embodiment, an extremely short channel FET is made by forming a metal layer over a wafer, depositing silicon dioxide over part of the metal layer, oxidizing the exposed metal, controllably etching a portion of the silicon dioxide to expose a small strip of the nonoxidized metal layer, electroplating the exposed metal strip, thereby to form an extremely narrow gate electrode, removing the deposited SiO.sub.2, the metal oxide and the remaining metal layer to leave only the gate electrode, and using the gate electrode as a mask for ion implanting source and drain regions. Since the gate electrode can be made so narrow, the channel region is correspondingly short to give extremely high frequency capabilities. Other embodiments are also described.
Complementary silicon gate MOS structure formed of a semiconductor body of silicon having a major surface with a first region of N conductivity type formed in the body and extending to the surface and a second region of P conductivity type formed in the body and extending to the surface. A P-channel MOS device is formed in the first region and an N-channel MOS device is formed in the second region to provide complementary devices in the body. Each of the P and N-channel devices has a polycrystalline gate structure in which the polycrystalline material is doped with a P-type impurity to make possible the matching of threshold voltages of both devices. In the method, complementary MOS devices are formed by the use of two separate etching operations on the polycrystalline material and forming relatively thick layers of silicon type material on the semiconductor body in separate operations.
A method for fabricating a semiconductor device includes the formation of a monitoring element in a substrate. The monitoring element has substantially the same structure and size as a circuit element on the device which is to be monitored. Polycrystalline electrodes are contacted to the semiconductor regions of the monitoring element and extend on an insulating film covering the surface of the substrate. The electrical characteristics of the monitoring element are measured by contacting probes of a measuring apparatus to portions of the polycrystalline electrodes.
