The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 03, 1996
Filed:
Jun. 07, 1995
John K Lowell, Round Rock, TX (US);
Advanced Micro Devices, Inc., Sunnyvale, CA (US);
Abstract
The method and apparatus of the present invention provides a fast, efficient, non-contact, non-destructive means of characterizing surface and near-surface regions of a semiconductor substrate subjected to high-energy (MeV) ion implantation through interpretation of a graph of surface charge versus modulation frequency of incident monochromatic light. The near-surface region of a semiconductor substrate is defined to extend from just below the surface of the semiconductor substrate to a depth of 0.8 .mu.m. Similar to existing SPV/SCI techniques, a semiconductor substrate is radiated with high photon energy such that energy bands become almost flat at the surface of the semiconductor substrate. Surface photovoltages produced at different modulation frequencies of incident light pulses are measured and recorded. Resultant surface charges are derived from measured surface photovoltages, and a graph is made of surface charge versus the modulation frequency of incident light pulses. Structural and material defects affecting the characteristics of the surface and near-surface regions of the semiconductor substrate may then be diagnosed from the resulting graph.