Browse Prior Art Database

Backside Etch of Silicon Nitride On Device Wafers

IP.com Disclosure Number: IPCOM000060104D
Original Publication Date: 1986-Feb-01
Included in the Prior Art Database: 2005-Mar-08
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Rosner, A: AUTHOR [+2]

Abstract

The removal of silicon nitride from the backside of a wafer can be facilitated by the modification of the wafer chuck in a Reactive Ion Etch (RIE) chamber to allow the backside nitride to be etched without affecting the device side and without using any protective layer over the device side.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 1

Backside Etch of Silicon Nitride On Device Wafers

The removal of silicon nitride from the backside of a wafer can be facilitated by the modification of the wafer chuck in a Reactive Ion Etch (RIE) chamber to allow the backside nitride to be etched without affecting the device side and without using any protective layer over the device side.

Referring to Fig. 1, previous RIE processes involved placing the wafer 10 on chuck 12 and then transporting them both for placement onto the bottom electrode 14 in the RIE chamber. Since the edge of wafer 10 overlaps the bottom electrode, the device side of the wafer, which is in contact with the electrode, is exposed to the plasma resulting in an unacceptable amount of attack. Modifying the dimensions of wafer chuck 12 as seen in Fig. 2 lifts the wafer 10 off of the bottom electrode 14, by approximately 10 mils. This separation avoids the frontside attack of the device side of the wafer. With this modification, no protective photoresist is needed for the device side.

The backside etch has been practiced using SF6 gas with this modified chuck, allowing the backside silicon nitride to be removed with a minimum of process steps.

Disclosed anonymously.

1