Browse Prior Art Database

Forming Complementary Field Effect Transistor Structure

IP.com Disclosure Number: IPCOM000080453D
Original Publication Date: 1973-Dec-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 75K

Publishing Venue

IBM

Related People

Antipov, I: AUTHOR [+5]

Abstract

This process produces a complementary self-aligned metal-oxide semiconductor structure.

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 53% of the total text.

Page 1 of 2

Forming Complementary Field Effect Transistor Structure

This process produces a complementary self-aligned metal-oxide semiconductor structure.

In this process, a relatively thick layer 10 of pyrolytic SiO(2) is deposited on an N- silicon substrate 12. As shown in Fig. 1, an opening 14 is formed in layer 10 using conventional photolithographic and differential etching techniques and P-type impurities introduced, preferably by ion implantation to produce region 16. In order to produce an alignment step for future reference, the exposed silicon in body 12 is etched with an etchant for silicon, and layer 10 subsequently removed.

The alignment step 18 is illustrated in Fig. 2. The P-type impurities in region 16 are then driven in, initially in an O(2) atmosphere to produce oxide layer 20 and subsequently in an N2, or other neutral atmosphere. N-type impurities are implanted at a relatively low energy to form N-type region 22 adjacent the surface of body 12, as shown in Fig. 2. The concentration of N-type impurity is sufficiently low so as not to overcome the P doping in region 16, as shown in Fig.
2. Layer 20 can then be removed and a new SiO(2) layer 24 deposited, preferably by pyrolytic deposition.

As shown in Fig. 3, openings are formed in layer 24 that define the device areas. Opening 25 defines a P channel field-effect transistor (FET) and opening 26 defines an N channel FET. Subsequently, a layer 28 of SiO(2) is formed either by thermal oxidation or pyrolytic deposition. Layer 30 of Si(3)N(4) and layer 32 of SiO(2) are then deposited over layer 28, as shown in...