| 摘要 |
1531909 Photo-electric control of alignment SIEMENS AG 16 Aug 1976 [3 Sept 1975] 33993/76 Heading G1A [Also in Division G2] Mask 91 is aligned with semi-conductor substrate 1 by means of at least four marks on the latter, which marks may take the form of Fig. 3. The mask has correspondingly located light transmissive areas (apertures) 51-54. During alignment a diaphragm 93 having apertures 931-934 blocks light except that passing through the mask alignment apertures. A converging beam 10 illuminates the substrate via mask and diaphragm. Light hitting the alignment recesses in the substrate surface is reflected away and does not reach photo-cells 84, 86 &c. Motors responsive to the photo-cell outputs cause movement of mask 91 in X and Y and rotation about a vertical axis to attain minimum detected intensity conditions, indicating alignment. Marks on the substrate may comprise arrays of recesses for fine adjustment purposes. Different wavelengths of illuminating light i.e. green or 436nm may be used for use with the rough and fine adjustments. |
