GB1194049A - Method of Making a Junction in a Semiconductor Body - Google Patents

Abstract

1,194,049. Semi-conductor devices. TEXAS INSTRUMENTS Inc. 31 Aug., 1967 [30 Dec., 1966], No. 39912/67. Heading H1K. Dopant is diffused into a localized region of a semi-conductor body 11 by forming a doped layer 13 on or in the body surface, exposing the required region to a focused beam of energy such as an electron beam or laser beam and thereby causing dopant from the layer to diffuse into the region, and subsequently removing the residue of the layer 13 by vapour etching. The resulting product (Fig. 4, not shown) is a body containing the diffused region 15 of Fig. 3-which may be of very small but accurately controlled dimensions and/or of complex geometry-eg in interdigitating patterns. The temporary layer 13 may be formed by conventional diffusion of dopant into the body surface, by liquid phase deposition of dopant on that surface, or by epitaxial deposition of doped semi-conductor on the surface. Removal of the layer by vapour etching may be facilitated by pulsed operation of an electron beam focused on to and rastered over the body surface. Such a beam may also be used to modify the impurity distribution in the diffused region by the out-diffusion method of Specification 1,194,048 and/or to produce a non-planar surface on the body as described in U.S.A. Specification 3,453,723. The invention is stated to be applicable to the doping of any conventional semi-conductor and also to semi-conductive dielectrics such as titanium dioxide.