Abstract: The tone or polarity of a patterned layer such as a photoresist mask on an integrated circuit or device substrate is reversed with substantially perfect alignment. A liquid planarizing layer is formed and hardened onto the patterned layer and underlying substrate, filling in spaces between pattern areas. The planarizing layer is then etched to a sufficient depth to expose the patterned layer. Finally, the patterned layer is dissolved away, leaving the reversed tone image which is constituted by the planarizing material in the spaces which were filled in. Modified embodiments enable large spaces between original pattern areas to be effectively reversed, and multi-level reversed tone images to be formed in which the reversed tone layers are thicker than the original layers.

Abstract: An analog-to-digital converter 10 employs a series of comparators 12, 14, 16 and 18. Each comparator includes at least one inverter consisting of a CMOS transistor pair including a P-channel transistor 22 and N-channel transistor 24. The threshold levels of the transistors 22, 24 are modified using focused ion beam implantation techniques to provide the comparators with monotonically increasing transistion levels.