Abstract: Fine featured devices are produced by a series of fabrication steps including exposing selective surface regions to irradiation, e.g. to an ion beam, generally to result in removal of masking material within irradiated regions. In most instances, subsequent etching is under conditions such that bared material is preferentially removed. Etch-removal and irradiation are such that overgrown material is of device quality at least in etched regions. The inventive process is of particular value in the fabrication of integrated circuits, e.g. circuits performing electronic and/or optical functions. The inventive process is expediently used in the fabrication of structures having minimum feature size of 1 micrometer and smaller. Patterning is dependent upon masking material of a maximum thickness of 100 .ANG..

Abstract: 36 We have discovered the III-V semiconductor layers with previously unattainably high effective hole concentrations can be produced by molecular growth processes (e.g. MBE) if an amphoteric dopant such as Be is used and if, during the growth of the highly doped III-V layer, the substrate is maintained at a temperature T.sub.g that is substantially lower than customarily used. For instance, a InGaAs layer with effective hole concentration 1.0.times.10.sup.20 cm.sup.-3 was grown at T.sub.g =450.degree. C., and a GaAs layer with effective hole concentration of 1.0.times.10.sup.20 cm.sup.-3 was grown at T.sub.g of 475.degree. C. The heavily doped III-V layers can be of device grade and can usefully be part of electronic devices such as high speed bipolar transistors.

Abstract: When high-vacuum methods are used in the manufacture of miniaturized devices such as, e.g., semiconductor integrated-circuit devices, device layers on a substrate are preferably patterned without breaking of the vacuum. Preferred patterning involves deposition of a semiconductor mask layer, generation of the pattern in the mask layer by ion deflected-beam writing, and transfer of the pattern by dry etching. When the mask layer is an epitaxial layer, further epitaxial layer deposition after patterning may proceed without removal of remaining mask layer material.

Abstract: The invention is a method and apparatus for growing group III-V semiconductor layers by molecular beam deposition in which a gaseous source is used to form a molecular beam comprising M.sub.2 or M.sub.4 molecules, where M is a group V element. Arsine and phosphine may be decomposed in a high temperature leak-source to provide As.sub.2 and P.sub.2 molecular beams for molecular beam epitaxy of group III-V semiconductors such as GaAs and InP.

Abstract: A semiconductor double heterostructure (DH) laser or spontaneous emitting diode is described which emits radiation in the infrared region of the spectrum from about 3.5 to 5.5 micrometers. The DH structure comprises a Group III-V lattice-matched system, in particular, Al.sub.y Ga.sub.1-y Sb--InAs.sub.x Sb.sub.1-x where 0.ltoreq.y.gtoreq.1 and 0.82.ltoreq..times..ltoreq.0.91, approximately.

Abstract: In the fabrication of double heterostructure GaAsAlGaAs junction lasers by molecular beam epitaxy, it has been found that suitably annealing the entire heterostructure increases the external quantum efficiency of the laser and reduces the room temperature threshold for lasing. Also described is a technique using relatively uncollimated beams to deposit continuously on the interior walls of the vacuum chamber fresh layers which getter deleterious contaminants. In addition, pyrolytic boron nitride, rather than graphite, effusion cells are utilized in order to reduce the amount of CO formation in the system.

Abstract: The average stress between contiguous layers of Al.sub.x Ga.sub.1.sub.-x As and Al.sub.y Ga.sub.1.sub.-y As (y > x) is reduced by the addition of phosphorus during the growth of the latter layer to produce the quaternary Al.sub.y Ga.sub.1.sub.-y As.sub.1.sub.-z P.sub.z instead of the ternary Al.sub.y Ga.sub.1.sub.-y As. In order to reduce the average stress to less than about 2 .times. 10.sup.8 dynes/cm.sup.2 the amount of phosphorus added should satisfy the condition: ##EQU1## Also described is a double heterostructure junction laser comprising a GaAs or AlGaAs active layer sandwiched between layers of AlGaAsP.