A technique for fabricating a semiconductor heterostructure by growth of a ternary semiconductor on a binary semiconductor substrate from a melt of the ternary semiconductor containing less than saturation of at least one common ingredient of both the binary and ternary semiconductors wherein in a single temperature step the binary semiconductor substrate is etched, a p-n junction with specific device characteristics is produced in the binary semiconductor substrate by diffusion of a dopant from the melt and a region of the ternary semiconductor of precise conductivity type and thickness is grown by virtue of a change in the melt characteristics when the etched binary semiconductor enters the melt.
After a liquid-phase epitaxial growth step by an n-type GaAs saturated solution is terminated, a substrate is temporarily dipped in an undoped GaAs saturated or supersaturated solution, and thereafter liquid-phase epitaxial growth is performed by a p-type Al.sub.x Ga.sub.1-x As saturated solution. Thus, the n-type GaAs saturated solution is prevented from being mixed into the p-type Al.sub.x Ga.sub.1-x As saturated solution to contaminate the same, whereby a solar battery of high quality can be obtained even if the number of times of crystallization is increased.
A luminescent or laser diode having a pn-junction surrounding an internally limited luminescent surface area and limiting current flow in the diode is produced by etching a select semiconductor substrate so as to produce a mesa dimensioned accordingly to the required luminescent surface area and without interruption epitaxially depositing and structuring required individual semiconductor material layers on the surfaces of the substrate and mesa to achieve the diode.
In manufacturing a semiconductor device by epitaxial growth from the liquid phase on a substrate of layers of gallium arsenide or gallium aluminum arsenide doped with elements such as germanium, the last growth melt is wiped off and the structure is cooled to a temperature from room temperature to 200.degree. C. During cooling, the structure's upper surface is contacted with a liquid gallium melt in such a manner that the doping elements present in the few remaining drops of the last growth melt not removed by the wiping off are dissolved.
