Recent progress in microelectronics

Abstract The DOFL microelectronics programme utilizes microminiature components assembled to or deposited directly upon small ceramic wafers. Passive components are usually applied by a combination of photolithography and etched circuit techniques. Special components such as transistors and inductors are assembled into cavities in the substrate. The system differs from the solid circuit and molecular electronics approaches in that individual components of desired characteristics are assembled as desired into a functional module. It differs from the micromodule system in that the size of the substrate is not fixed, and a relatively large number of components are applied to a single wafer to comprise a specific functional unit. Improvements in the performance of previously announced digital units has been made. Switching speeds have been increased from 20 kc/s to 5 Mc/s; stability and uniformity have been improved by the use of chemically deposited resistors and wiring. In order to speed the application to military electronics and missile guidance applications, recent effort has been directed toward accomplishing the transition from digital to linear circuits. A 400 Mc/s command receiver is being designed to fit in a volume of less than 1 in 3 . The I.F. amplifier and F.M. discriminator have been completed. The amplifier has a centre frequency of 30 Mc/s, a gain of 100 dB and a bandwidth of 2 Mc/s. The discriminator occupies a single wafer approximately 0.05 in 3 . The major remaining problem is the R.F. head which will occupy approximately 1 2 in 3 . A small production facility for the fabrication of prototype quantities of wafers has been completed and data is being gathered on cost and reliability.