Laser system personalizes 0.35-um gate array
05/01/1998
Laser system personalizes 0.35-?m gate array
A newly upgraded laser micromachining system provides rapid personalization of 0.35-?m gate array devices, with improvements of throughput and accuracy.
Developed by Chip Express Corp., Santa Clara, CA, the QuICk laser system is used for fabricating a laser programmable gate array, a fast-turn high performance gate array prototype. The base wafers are fabricated with interconnection layers fully completed. The laser technique selectively removes specific metalization points to personalize the arrays. One die is processed at a time, and pre-defined links are disconnected by the laser system. No photolithography masks are required.
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Before and after illustrations of the cutting accuracy of the QuICk laser programmable gate array.
Chip Express enhanced the QuICk system performance by doubling throughput so that a 0.35-?m device with over 500,000 gates could be customized in two hours. Laser pulse maximum repetition rate was increased to 50 kHz, implying that the laser machine is capable of completing about 50,000 cuts/sec (compared to the previous performance of 20,000 cuts/sec) of the die links.
Ofer Hareuveni, VP of system development, noted further features of the laser upgrade, "The noisy Krypton lamp pumped laser was replaced with a very stable diode pump laser manufactured by Lightwave Electronics of Mountain View, CA. This increases the pulse repetition while preserving energy stability. Hardware and software were improved for better overlay and focus accuracy, and for better laser energy control. Servo control of the positioning system was also improved."
The move to 300-mm wafers will not be a concern. "For the laser system, the wafer`s size has no significance. Wafers are diced, and the machine personalizes one die at a time. A single die is placed on the machine stage to be cut by the laser," Hareuveni explained.
The upgrading development process on the QuICk laser system took about one year. Working with Chartered Semiconductor Manufacturing of Singapore, Chip Express plans to offer the 0.35-?m gate array, the CX3000, to beta customers this year. - L.S.