Abstract: A method and apparatus are disclosed for identifying molecular structures within a sample substance using a monolithic array of test sites formed on a substrate upon which the sample substance is applied. Each test site includes probes formed therein to bond with a predetermined target molecular structure or structures. A signal is applied to the test sites and certain electrical, mechanical and/or optical properties of the test sites are detected to determine which probes have bonded to an associated target molecular structure.

Abstract: A new III-V buffer or passivation material is described which is produced by low temperature growth (LTG) of III-V compounds. The material has unique and desirable properties, particularly for closely spaced, submicron gate length active III-V semiconductor FET devices, such as HEMT's, MESFET's and MISFET's. The LTG material is grown under ambient conditions which incorporate an excess of the more volatile of the III-V species into the grown material. The new material is crystalline, highly resistive, relatively insensitive to light, and can be overgrown with high quality III-V active layers or used as a passivation material to insulate and protect active device structures.

Abstract: A new III-IV buffer material is described which is produced by low temperature growth of III-V compounds by MBE that has unique and desirable properties, particularly for closely spaced, submicron gate length active III-V semiconductor devices, such as HEMT's, MESFET's and MISFET's. In the case of the III-V material, GaAs, the buffer is grown under arsenic stable growth conditions, at a growth rate of 1 micron/hour, and at a substrate temperature preferably in the range of 150 to about 300.degree. C. The new material is crystalline, highly resistive, optically inactive, and can be overgrown with high quality III-V active layers.