| United States Patent | 6,429,890 |
| Corbett | August 6, 2002 |
A laser marking apparatus and method for marking the surface of a semiconductor chip are described herein. A laser beam is directed to a location on the surface of the chip where a laser reactive material, such as a pigment containing epoxy is present. The heat associated with the laser beam causes the laser reactive material to fuse to the surface of the chip creating a visibly distinct mark in contrast to the rest of the surface of the chip. Only reactive material contacted by the laser fuses to the chip surface, and the remaining residue on the non-irradiated portion can be readily removed.
| Inventors: | Corbett; Tim J. (Boise, ID) |
| Assignee: | Micron Technology, Inc. (Boise, ID) |
| Appl. No.: | 942136 |
| Filed: | August 29, 2001 |
| Current U.S. Class: | 347/262; 347/224; 219/121.6 |
| Intern'l Class: | B41J 002/435; B23K 026/00 |
| Field of Search: | 347/224,262,264 430/270.1,298 219/121.6,121.61,121.47 |
| 3751587 | Aug., 1973 | Insler et al. | 358/481. |
| 4148057 | Apr., 1979 | Jesse | 347/232. |
| 4375025 | Feb., 1983 | Carlson | 219/121. |
| 4561541 | Dec., 1985 | Lawrence | 206/722. |
| 4585931 | Apr., 1986 | Duncan et al. | 235/462. |
| 4638144 | Jan., 1987 | Latta, Jr. | 219/121. |
| 4707722 | Nov., 1987 | Folk et al. | 257/741. |
| 4719502 | Jan., 1988 | Ikeya et al. | 257/793. |
| 4753863 | Jun., 1988 | Spanjer | 430/138. |
| 4791267 | Dec., 1988 | Yokoyama et al. | 219/121. |
| 4861620 | Aug., 1989 | Azuma et al. | 427/556. |
| 4945204 | Jul., 1990 | Nakamura et al. | 219/121. |
| 5030551 | Jul., 1991 | Herren et al. | 430/495. |
| 5157412 | Oct., 1992 | Kleinschmidt et al. | 347/232. |
| 5206280 | Apr., 1993 | Williams | 524/409. |
| 5262470 | Nov., 1993 | Shimotsuma et al. | 524/496. |
| 5329090 | Jul., 1994 | Woelki et al. | 219/121. |
| 5346802 | Sep., 1994 | Ohbachi et al. | 430/270. |
| 5357077 | Oct., 1994 | Tsuruta | 219/121. |
| 5373039 | Dec., 1994 | Sakai et al. | 524/100. |
| 5413629 | May., 1995 | Yasui et al. | 106/31. |
| 5445923 | Aug., 1995 | Takahashi et al. | 430/340. |
| 5838361 | Nov., 1998 | Corbett | 347/262. |
| 6108026 | Aug., 2000 | Corbett | 347/262. |