Patent Number: 
Section: abstract

A radiation source for use in lithography. The radiation source comprising a pn-junction disposed on a substrate that can be reverse-biased to cause avalanche breakdown and emission of UV or DUV radiation by deceleration of electrons accelerated into an n-type region of the pn-junction. The radiation source can have a low operating voltage, a high switching speed, and provides great design freedom. High intensity can be provided, e.g., by the use of large or multiple sources. The pn-junction can be doped with impurities to increase emission of radiation at a desired frequency and increase the efficiency of the device. For protection, the pn-junction may be covered by a layer of transparent oxide. By reverse biasing the pn-junction with a potential difference at least 4V, radiation of wavelength 300 nm or less can be obtained. The pn-junction source of the present invention can replace conventional radiation sources and be using in connection with a mask/contrast device, or can be used to replace both the conventional radiation source and the mask/contrast device.