Browse Prior Art Database

Fabrication Of A MISIM Transistor Structure

IP.com Disclosure Number: IPCOM000078161D
Original Publication Date: 1972-Nov-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

Crowder, BL: AUTHOR [+2]

Abstract

A new type of bipolar transistor, for use as a substitute for other known bipolar transistors, in logic circuits, memories, etc., has been proposed Such novel bipolar transistor will comprise the following layers, namely, a metal-insulator-semiconductor-insulator-metal (MISIM).

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 96% of the total text.

Page 1 of 2

Fabrication Of A MISIM Transistor Structure

A new type of bipolar transistor, for use as a substitute for other known bipolar transistors, in logic circuits, memories, etc., has been proposed Such novel bipolar transistor will comprise the following layers, namely, a metal- insulator-semiconductor-insulator-metal (MISIM).

Although such MISIM transistor (see Fig. 1) is believed to have improved switching characteristics over commercially available transistors, there are no known ways of making it. The proposed method of manufacture consists of the following steps:

A p-wafer of silicon (see Fig. 2) is diffused with a high concentration of arsenic and such arsenic-diffused layer serves as the bottom metal contact of the ultimate MISIM device. A 5000 Angstroms thick boron-doped epitaxy layer is grown on the doped p/-/ silicon substrate to achieve a p type silicon layer. Subsequent to this step, arsenic is uniformly implanted by ion bombardment in the epitaxially grown layer to a concentration level that is about 1/3 that of the boron. Finally, a high concentration of arsenic is diffused into the top of the wafer to form the other metal contact of the MISIM device.

During the latter arsenic diffusion step (see Fig. 3), the boron in the epitaxial layer will diffuse rapidly towards the slow moving arsenic of the boron-arsenic interfaces. Severe depletion of boron will occur at these two interfaces, causing compensation insulating layers (I) of the device to form.

1

Page...