| 摘要 |
1332775 Semi-conductor processes RCA CORPORATION 29 March 1972 [7 April 1971] 14697/72 Heading H1K A region 16 of a desired conductivity type is formed in the surface of a single crystal semiconductor body 10 by diffusion of a dopant from a layer 14 of a single crystal material the crystalline lattice of which matches that of the material of the body 10. At least part of the layer 14 is subsequently removed using an etchant which selectively attacks the material of the layer 14, leaving the body 10 substantially unetched. The layer 14 is preferably deposited on the body 10 by liquid phase epitaxy. The body 10 may be of GaAs (e.g. containing Si as a dopant) or Al x Ga 1-x As (x less than 0À4), in which case the layer 14 may be of Al x Ga 1-x As (x greater than 0À4) doped with Zn, Ge, Cd, Te, S or Sn. Boiling HCl preferentially etches the lastnamed material. A part of the layer 14 may be retained to serve as an ohmic contact to the region 16. Diffusion of the region 16 may take place during or after deposition of the layer 14. The matching of the crystalline lattices is stated to reduce the surface damage produced in GaAs or AlGaAs during conventional gaseous diffusion processes.
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