| United States Patent | 6,420,792 |
| Guldi , et al. | July 16, 2002 |
The marking of identification and orientation information along the edge (E) of a semiconductor wafer (20, 20') is disclosed. The information may be marked by way of laser marking at one or more locations (10) along a flat portion (14) or bevel (12.sub.t, 12.sub.b) of the edge (E) of the wafer (20, 20'). The wafer marking (10) may be encoded, for example by way of a 2-D bar code. A system (30) for reading the identification information from wafers (20, 20') in a carrier (32) is also disclosed. The system (30) includes a sensor (36) for sensing reflected light from the wafer markings (10) along the wafer edge (E), and for decoding identification and orientation therefrom. A motor (38), under the control of feedback (RFB) from the sensor (36), rotates the wafers (20, 20') by way of a roller (39) until the wafer marking (10) is in view by the sensor (36). A processing system (40), which includes a rotatable chuck (41) upon which the wafer (20, 20') is placed, is also disclosed. The processing system (40) also includes a sensor (36) for sensing identification and orientation information from the wafer edge (E), and a process control computer (46) that receive signals corresponding to the identification information, for purposes of manufacturing data logging and process control.
| Inventors: | Guldi; Richard L. (Dallas, TX); Melcher; Keith W. (McKinney, TX); Williston; John (Plano, TX) |
| Assignee: | Texas Instruments Incorporated (Dallas, TX) |
| Appl. No.: | 661963 |
| Filed: | September 14, 2000 |
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