Browse Prior Art Database

Subcollector Pedestal Structures

IP.com Disclosure Number: IPCOM000078703D
Original Publication Date: 1973-Feb-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 2 page(s) / 92K

Publishing Venue

IBM

Related People

Doo, VY: AUTHOR

Abstract

As shown, the devices can be formed from a P substrate, in which an N+ subcollector region is initially formed by ion implantation with subsequent growing of an N- epitaxial layers, with subsequent formation of N+ pedestals on the subcollector by ion implantation through the N- epi region.

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Subcollector Pedestal Structures

As shown, the devices can be formed from a P substrate, in which an N+ subcollector region is initially formed by ion implantation with subsequent growing of an N- epitaxial layers, with subsequent formation of N+ pedestals on the subcollector by ion implantation through the N- epi region.

As shown in Fig. 1, a P- silicon substrate is coated with suitable masking material such as CVD/SiO(2), etc., in which a subcollector pattern is defined by conventional photolithographic techniques. After opening of the diffusion window, N+ dopants (such as arsenic) are implanted into the exposed silicon a few tenths of a micron below the surface, so that the substrates surface maintain its original P- doping as a majority carrier. In this step, implantation induced damages are limited to the implanted region, whereby the silicon surface region maintains its original perfection.

In the next operation as illustrated in Fig. 2, the diffusion mask is stripped followed by deposition of an N- silicon epitaxial layer on the P- substrate, with the eventual deposition of a masking material which is suitably patterned by photolithographic techniques to define a pedestal pattern for constraining suitable implantation of N+ (e.g. AS) pedestals, as shown in Fig. 3.

The resultant structure can have incorporated various transistors, resistors, and isolation necessary for any specific application, by a suitable incorporation of PN dopants in appropriate sites....