Method for nondestructive measurement of dopant concentrations and profiles in the drift region of certain semiconductor devices
US6294919A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 11, 1999 |
| Grant date | Sep 25, 2001 |
| Priority date | — |
| Expiry date | Mar 11, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.