Patent Number: 6,294,919

Title: Method for nondestructive measurement of dopant concentrations and profiles in the drift region of certain semiconductor devices

Abstract: A method is provided for determining dopant impurity concentration N.sub.D in certain semiconductor devices, such as high voltage lateral double diffused metal oxide semiconductor (HV LDMOS) transistors. Such a device is scanned along its length by a beam of radiant energy (e.g., a laser beam focused through a microscope onto the device) while the device is reverse biased by a voltage V. A resulting beam induced current signal measures a depletion width W, for a given bias voltage V, the widths W increasing with increasing bias voltages V. From a series of respective voltages V and widths W a profile of corresponding dopant concentrations N.sub.D is determined using a suitable mathematical algorithm.

Inventors: Baumgart; Helmut (Mahopac, NY)

Assignee: Infineon Technologies AG

International Classification: H01L 21/66 (20060101); G01R 031/28 ()

Expiration Date: 09/25/2018