Browse Prior Art Database

Manufacture of Semiconductor Devices

IP.com Disclosure Number: IPCOM000097211D
Original Publication Date: 1962-Jul-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 22K

Publishing Venue

IBM

Related People

LeMay, CZ: AUTHOR

Abstract

Semiconductor devices are produced by a method which involves epitaxial growth from the vapor phase of semiconducting layers onto a seed crystal. TEFLON* applied to the surface of the seed masks the surface against epitaxial growth. However, the growth process affects the TEFLON in such a way as to make it difficult, if not impossible, to remove it.

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Manufacture of Semiconductor Devices

Semiconductor devices are produced by a method which involves epitaxial growth from the vapor phase of semiconducting layers onto a seed crystal. TEFLON* applied to the surface of the seed masks the surface against epitaxial growth. However, the growth process affects the TEFLON in such a way as to make it difficult, if not impossible, to remove it.

If the TEFLON be applied to a seed which is subjected to normal growth conditions but without the presence of hydrogen in the growth tube, it can readily be removed by such laboratory etches as white etch (1 part HF, 5 parts H(2)O) or superoxol etch (1 part HF, 1 part H(2)O(2), 2 parts H(2)O). Thus, after removal of the initially applied TEFLON, a second TEFLON configuration can then be used, or, alternatively, epitaxial growth conditions can be produced over the entire surface of the seed crystal. An example of the manner in which the alternative technique can be used to produce a device is given.

A small TEFLON circle is evaporated onto an N+ seed crystal. An intrinsic region is then grown around the small circle (left drawing). The circle is then removed with a chemical etch, such as one of the mentioned etches. Finally, an epitaxial layer, compatible with the original N+ substrate region, is grown onto the substrate region. The grown layer is doped to be of P+ conductivity thus producing the structure of the right drawing. Contacts are then applied to the top and bottom surface...