摘要:
A periodic table group III-IV field-effect transistor device is described. The disclosed device uses a single metalization for ohmic and Schottky barrier contacts, permanent plural etch stop layers, employs a non-alloyed ohmic connection semiconductor layer and includes a permanent semiconductor material-comprised secondary mask element, a mask element which can be grown epitaxially during wafer fabrication to perform useful functions in both the device processing and device utilization environments. The device of the invention may be achieved with both an all optical lithographic process and a combined optical and electron beam lithographic process The disclosed device provides a field-effect transistor of reduced fabrication cost, increased dimensional accuracy and state of the art electrical performance.
摘要:
An integrated circuit substrate via-hole fabrication arrangement providing for accurate determination of via-hole size and via-hole registration through use of a calibrated pattern formed into the integrated circuit substrate during portions of the normal circuit fabrication process. Initiation of the via-hole and fabrication of the calibrated pattern from one surface, such as the front side, of the integrated circuit wafer and completion of the via-hole from the opposite surface of the wafer are contemplated. The calibrated pattern may be one of several possible physical configurations and of selected dimensions usable with the process, materials and circuitry of the device being fabricated. Use of the invention in fabricating ground conductor-connected via conductors for gigahertz radio frequency-capable integrated circuits of the monolithic or mixed hybrid with monolithic type and having a ground plane element is contemplated.
摘要:
A method and system for measuring whole-wafer etch pit density (.rho..sub.D) is disclosed in which an etch GaAs wafer is tested for fractional transmission at a plurality of points over its surface. The fractional transmission (T) of light through the wafer is detected, amplified and fed to a computer where at least two points of transmission measurement are selected for calibration. From these measurements, together with an estimate of the average etch pit size (area), the values for fractional transmission in regions of low etch pit density T.sub.O and high etch pit density T.sub.E may be calculated, and used to convert transmission data directly to etch pit density (.rho..sub.D) according to the equation ##EQU1##