DuPont Photomasks, Inc. was engaged in supplying photomasks. Photomasks are the customized etched plates of high-purity quartz or glass that are used by semiconductor makers to transfer circuit patterns onto silicon wafers. The company also supplies major chip makers, including AMD, IBM, Philips, STMicroelectronics, Texas Instruments and United Microelectronics. It also makes photomasks used to produce flat-panel displays, disk drive heads, microelectromechanical products and biochips. The company was located in Round Rock, TX.