Planar beam-lead gallium arsenide electroluminescent arrays

The application of planar and beam-lead technologies to GaAs has permitted the fabrication of integrated arrays of electroluminescent diodes. The arrays, to date, have consisted of 4 × 4 matrices, and larger arrays are now considered to be feasible. The diodes are Zn-diffused on 0.010-in centers, with Zn masking being provided by a composite structure of thermally deposited SiO2and phosphosilicate glass layers. Air isolation is used between the individual diodes with the interconnections being made by means of the beam leads. External efficiencies for light exiting from the back of the arrays have been as high as 0.003 with the variation within the arrays being less than ± 10 percent. The arrays have been used to optically trigger matching arrays of Si photosensitive p-n-p-n´s. They also show promise in memory applications, where they may compete favorably with laser activated memory systems.