Production Engineering Measure for an Electron-Beam Machine and Microwave Transistors.
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)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1972
- Accession Number
- AD0900280
Entities
People
- Daniel Ch'en
- Gilbert L. Varnell
- Roger R. Webster
Organizations
- Texas Instruments