| 摘要 |
1,149,109. Semi-conductor devices. INTERNATIONAL BUSINESS MACHINES CORP. 6 March, 1968 [15 June, 1967], No. 11005/68. Heading H1K. A semi-conductor compound having at least three components is deposited by liquid phase epitaxy on a solid crystalline substrate. The composition of the compound is determined by the rate of cooling of the melt. A mixture of Ga, Al and an excess of pure Ga As is melted in an inert atmosphere, a substrate of GaAs, which may be doped with Sn, is inserted and the system allowed to achieve equilibrium. The temperature of the melt is then reduced at the desired rate to epitaxially deposit a layer of Ga 1-x Al x As (0 < x < 1). The melt may also contain Te as a dopant. A PN junction may be obtained by stopping the cooling, introducing Zn into the melt, raising the temperature slightly and allowing the system to achieve equilibrium, and then continuing the cooling at the previous rate. The composition of the deposited layer may be altered to form a heterojunction by abruptly changing the rate of cooling. If the cooling rate exceeds 10‹ C. per minute essentially pure GaAs is deposited. A gradual variation in the composition of the deposited layer may be achieved by slowly altering the cooling rate. A light-emitting diode may be produced by forming a PN junction in the epitaxial layer, lapping off the GaAs substrate, and cleaving on four sides. The diode may be provided with an anti-reflection coating in the form of a layer of epoxy resin. An optoelectronic transistor may be produced by growing a layer of N-type Ga 1-x Al x As followed by a layer of GaAs on a P-type GaAs substrate. The epitaxial GaAs layer is P-type and may be doped by diffusion after growth or by counterdoping during growth. The compound may also be Ga 1-x Al x P (0 < x < 1) deposited on a GaP substrate. |
