公开(公告)号：US20010040905A1

公开(公告)日：2001-11-15

申请号：US09891928

申请日：2001-06-25

Applicant: Lambda Physik AG

Inventor： Uwe Stamm ,  Hans-Stephan Albrecht ,  Uwe Leinhos ,  Wolfgang Zschocke

IPC: H01S003/13

CPC classification number: G01J1/58

Abstract: An ultraviolet light detection system is provided wherein a dark current background growth rate with total accumulated exposure dose is avoided, and parameters of an ultraviolet radiation source such as an ArF-excimer laser may be monitored without rapid degradation of the signal by the superposition of the dark current background over a desired signal. The invention provides a detector including a light sensitive element having a frequency conversion coating on its surface. The coating is preferably directly on the light sensitive element, absorbing incident ultraviolet light and re-emitting visible light in a direction toward the light sensitive element. The coating minimizes a dark current background that would otherwise appear when incident ultraviolet light impinges directly upon the light sensitive element, and thereby extends a lifetime of the light sensitive element. The detector is useful for detecting a wide range of ultraviolet wavelengths, and is particularly useful in solving the dark current growth rate with total accumulated exposure dose problem associated with detecting incident radiation under 240 nm.