| 摘要 |
PURPOSE:To obtain the right quantity of exposure by preparing several photo detectors corresponding to the interference filters to analyze the spectrum of the light, and by weighting the converted electric signal so that the spectral sensitivity characteristics of the light receiving system coincides with those of the photo resist. CONSTITUTION:The light of the ultra high pressure mercury lamp 1 passes the elliptical concave mirror 2, the mirror 3, the collimator 4, the L39 filter and the fly's eye lens 7, and is reflected by the mirror 8. This reflected light passes the condenser lens 9 and illuminates the wafer through the mask 10. Thus the photo resist is exposed to the light. The luminous flux which passed through the mirror 8 is divided into the spectral lines, that is, i-line, g-line and h-line by the dichroic mirrors 11, 12 and 13 respectively, and are converted to the electric signals by photoelectric conversion elements 14, 15 and 16. After being amplified and weighted by the individual gains of the amplifier 17i, 17g and 17h, these signals are synthesized by the amplifier 17t. This synthesized signal is sent out as the photo detection signal Vout, which is arbitrarily and easily set by the variable resister so as to coincide with the value of the photo resist, and therefore enabled to obtain the reasonable quantity of exposure. |
