Patent Number: 6,294,918

Title: Method for locating weak circuit having insufficient driving current in IC chips

Abstract: A method for locating a weak circuit that has insufficient driving current in an IC chip is described. In the method, an active surface of an IC chip can be irradiated by an electron beam point-to-point to determine a suitable loading current that will cause functionality failure in the IC circuit scanned. The functionality failure can be detected by a functionality tester that is mounted juxtaposed to the electron beam and functions simultaneously with the scanning motion. A threshold current is then determined as the loading current that causes failure and is used to scan the complete surface of the IC chip for locating all the weak circuits that may have insufficient driving currents in the chip. A suitable loading current may be selected between about 0.1 .mu.A and about 100 .mu.A for testing of most IC devices.

Inventors: Hung; Hui-Chuan (Chu-Pei, TW)

Assignee: Taiwan Semiconductor Manufacturing Company, Ltd

International Classification: G01R 31/28 (20060101); G01R 31/307 (20060101); G01R 031/00 ()

Expiration Date: 09/25/2018