Mary Louise Martinez

US Patent:

20030153192, Aug 14, 2003

Filed:

Feb 13, 2002

Appl. No.:

10/076130

Inventors:

Sailesh Suthar - Portland OR, US
Paul Hack - Portland OR, US
Syed Sarwar - Hillsboro OR, US
Mary Martinez - San Jose CA, US

International Classification:

H01L021/00
H01L021/311

US Classification:

438/695000, 438/008000

Abstract:

semiconductor chip. The method comprises etching a backside of the semiconductor chip, the frontside including a first well with a first type of doping and a second well with a second type of doping; monitoring a backside of the semiconductor chip during etching; and determining when a first portion of the backside over one of the first and second wells differs from a second portion of the backside over the other of the first and second wells. A method for etch endpoint detection includes etching a backside of a semiconductor chip, the semiconductor chip having at least one doped well formed proximate a frontside of the semiconductor chip; monitoring the backside of the semiconductor chip during etching until at least one doped well becomes visible; and stopping etching after the doped well becoming visible.