Sic p-n junction electroluminescent diode with a donor concentration diminishing from the junction to one surface and an acceptor concentration increasing in the same region

摘要: 1,201,428. Electroluminescence. GENERAL ELECTRIC CO. 22 Oct., 1968 [24 Nov., 1967], No. 50128/68. Heading C4S. [Also in Divisions H1 and H5] A SiC electroluminescent PN junction diode comprises a crystal the bulk of which is N-type containing donor; has diffused region next to one surface donor concentration decreases towards an acceptor greater than at inwardly from surface, concentrations being such that have substantial gradients opposite directions. The diodes are grown by diffusing B Al into N-doped α-SiC crystals. Concentrations specified. Polished crystals 1b separated porous graphite spacers 15 placed crucible 7 having dense outer inner walls 12, 13. space between filled with protective charge 14 Si C powder mixed dopants, dopant may be boric acid. heated resistance furnace (see Division H5) argon stream 1300‹, 1450‹ 1600‹ C., each for 1 hour, then diffusion temperature, preferably 2200‹ C. At 1300‹ N diffuses out crystals, reacts form uniformly distributed Al. further outgassing occurs. maintains vapour pressure chamber prevents dissociation crytals whilst allowing diffuse out, N, becoming equal charge. reused initially. P-type layer on both sides, removed grinding, they cut square elements. dispersion organic solution applied P-layer Al-Si eutectic Au-Ta alloy contact fused N-layer. element soldered or cemented using Au-epoxy resin Au-plated metal base-plate transistor type header. gold wire bonded contact, alternatively Fe NiCr header enclosed cover lens all glass cap.