An automatic X-ray alignment/exposure system developed for VLSI application involving printed linewidths in the one micron and submicron range is described. This paper focuses on the automatic alignment system designed to meet the specific overlay requirements for such applications. Other key elements of this fully automated, high throughput wafer exposure system are briefly presented.
W T Novak,
"X-Ray Lithography Alignment System", Proc. SPIE 0448, X-Ray Lithography and Applications of Soft X-Rays to Technology, (19 March 1984); doi: 10.1117/12.939213; https://doi.org/10.1117/12.939213