WERKWIJZE TER VERVAARDIGING VAN LICHTEMITTERENDE HALFGELEIDERINRICHTINGEN.

摘要

1300067 Electroluminescence TEXAS INSTRUMENTS Inc 1 Dec 1969 [23 Jan 1969] 58518/69 Heading C4S [Also in Division H1] The invention makes use of the high rate of diffusion of zinc along the interface between an AIIIBV body containing phosphorus and a masking layer of (phosphorus-doped) silicon oxide. A somewhat less high zinc diffusion rate prevails with non-phosphidic AIIIBV compounds which may also be used. In a particular embodiment an n-type gallium arsenophosphide body 11 is provided with an apertured silicon nitride mask 12 and the assembly then coated with a layer 13 of phosphorus-doped silicon oxide which lies on the nitride mask and directly on the semiconductor where the nitride mask is apertured. An annular portion 14 of the oxide is removed contiguous with the edge of the aperture in the nitride and the structure is then heated in an atmosphere containing zinc. The nitride-semiconductor interface does not favour lateral zinc diffusion which however occurs under the oxide so that in the structure shown the deeper part of the pn-junction 16 is outlined by the nitride mask and the shallower less heavily doped part is formed as a result of lateral diffusion under the oxide. Both masking layers are removed and the body recoated with an oxide layer in which an annular aperture is formed so that an evaporated zinc-gold electrode may be provided on the thicker part of the p-type region. (Gold-antimony may be used to contact the n-type body.) The resultant diode emits light of high intensity from the shallow part of the junction through the overlying oxide. A similar embodiment (Figs. 6-10, not shown), utilizes a rectangular slot in the oxide mask to provide a rectangular p-type region of tapered thickness with a deep highly doped portion at one edge at the position of the diffusion slot.