摘要 |
A cross-mask and cross-mask holder with improved adjustment means. A cross-mask holder allows adjustment of a cross-mask in the x, y and theta directions. The cross-mask may be adjusted in the x and the y directions through use of screws on the side of the holder and may be adjusted in the theta direction by turning a tube which contains the cross-mask. The invention further discloses the use of an umbrella and cover assembly to reduce light source background noise which improves the alignment signal on an oscilloscope during processing of semiconductor wafers in a stepper machine.
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