Accession Number : AD0900280

Title :   Production Engineering Measure for an Electron-Beam Machine and Microwave Transistors.

Descriptive Note : Quarterly rept. no. 3, 1 Oct 71-1 Jan 72,

Corporate Author : TEXAS INSTRUMENTS INC DALLAS

Personal Author(s) : Webster, Roger R. ; Varnell, Gilbert L. ; Ch'en, Daniel

Report Date : 01 JAN 1972

Pagination or Media Count : 38

Abstract : Significant steps were made toward establishing a fully computer-controlled electron-beam delineation capability for fabrication of microwave transistors. The first lot of slices (EBT-1) was processed through all the microwave transistor 'masking' levels to establish electron resist and etching processes. Significant problems were not encountered using PMMA RESIST UNTIL THE CONTACT 'MASKING' LEVEL. A CHANGE IN THE ETCH RATE OF THE SPUTTERED GOLD DUE TO ELECTRON-BEAM IRRADIATION CAUSED SEVERE UNDERCUTTING OF THE EMITTER FINGERS USING PMMA and conventional chemical etching techniques. A negative electron resist polystyrene was utilized on Lot EBT-5 to take advantage of this etch rate differential. Polystyrene enabled delineation of 0.7 m emitter contact fingers on all slices in this lot. Evaluation of the transistors from Lot EBT-5 is in progress. Excellent progress was made this quarter toward fully automating pattern registration for fabrication of 6 GHz transistors. Lots EBT-4 and EBT-5 were used to test the alignment capability of the automatic pattern registration (APR) system on wafers going through the 6 GHz transistor process. Another major step toward fully computer- controlled e-beam delineation was accomplished through assembly and check-out of the electrical and mechanical hardware necessary for the step-and-repeat operation. (Author, modified-PL)

Descriptors :   (*TRANSISTORS, ELECTRON BEAMS), MANUFACTURING, MICROWAVE FREQUENCY, ACRYLIC RESINS, MASKING, GOLD, ETCHING, SPUTTERING, NITRIDES, SILICON, STYRENE PLASTICS, SUBSTRATES, C BAND, OXIDES, DOPING, BORON, ARSENIC.

Subject Categories : Electrical and Electronic Equipment
      Particle Accelerators

Distribution Statement : APPROVED FOR PUBLIC RELEASE