Method for fabricating integrated circuits with patterned thermal adjustment layers for design optimization

摘要

An integrated circuit may include a substrate in which transistors are formed. The transistors may be associated with blocks of circuitry. Some of the blocks of circuitry may be configured to reduce leakage current. A selected subset of the blocks of circuitry may be selectively heated to reduce the channel length of their transistors through dopant diffusion and thereby strengthen those blocks of circuitry relative to the other blocks of circuitry. Selective heating may be implemented by coating the blocks of circuitry on the integrated circuit with a patterned layer of material such as a patterned anti-reflection coating formed of amorphous carbon or a reflective coating. During application of infrared light, the coated and uncoated areas will rise to different temperatures, selectively strengthening desired blocks of circuitry on the integrated circuit.

主权项

1. A method for fabricating an integrated circuit, said method comprising:
forming blocks of transistors in a semiconductor substrate; strengthening a selected first subset of the blocks of transistors by reducing the channel lengths of the transistors in the first subset of the blocks, wherein reducing the channel lengths of the transistors in the first subset of the blocks comprises:
forming a patterned layer of material on the semiconductor substrate to cover the selected first subset of the blocks of transistors and leaving a second subset of the blocks of transistors uncovered by the patterned layer of material; andapplying heat to the substrate that heats the selected first subset of the blocks of transistors covered by the patterned layer of material to a different temperature than the second subset of the blocks of transistors that is not covered by the patterned layer of material such that dopant diffuses more in the transistors of the selected first subset of the blocks of transistors than in the transistors of the second subset of the blocks of transistors, the channel lengths of the transistors of the selected first subset of the blocks are reduced by more than the channel lengths of the transistors of the second subset of the blocks of transistors, and the strengths of the transistors of the selected first subset of the blocks are increased; and removing the patterned layer of material.