Monitoring and test structures for silicon etching

• US 6,599,761 B2
• Filed: 07/26/2001
• Issued: 07/29/2003
• Est. Priority Date: 07/26/2001
• Status: Expired due to Fees

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Co. (HP Inc.)
• Inventors: Leith, Steven D., Edwards, William, Schulte, Donald W., Obert, Jeffrey S., Emery, Timothy R., Hess, Jeffery S.
• Primary Examiner(s): Niebling, John F.
• Assistant Examiner(s): Roman, Angel
• Application Number:
  US09/917,067
• Publication Number:
  US 20030022397A1
• Time in Patent Office: 733 Days
• Field of Search: 438/10, 438/11, 438/17, 438/18, 438/21
• US Class Current: 438/11
• CPC Class Codes: B41J 2/16 Production of nozzles
• CPC Class Codes: B41J 2/1626 etching
• CPC Class Codes: H01L 21/67253 Process monitoring, e.g. flow or thickness monitoring
• CPC Class Codes: H01L 22/26 Acting in response to an ongoing measurement without interruption of processing, e.g. endpoint detection, in-situ thickness measurement endpoint detection arrangements in CMP apparatus B24B37/013, in discharge apparatus H01J37/32
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A through-substrate etching process is monitored by providing a sacrificial electrode in proximity to a desired etch window on the substrate. An etch process is performed on the substrate. The etch process is monitored by measuring an electrical property of either the substrate or the sacrificial electrode or both.

Claims

1. A method of monitoring a through-substrate etching process, comprising the steps of:

providing a sacrificial electrode in proximity to a desired etch window;

performing an etch process on the substrate; and

monitoring the etch by measuring an electrical property of at least one of the sacrificial electrode and the substrate, wherein the sacrificial electrode intersects the desired etch window.

2. The method of claim 1 wherein the sacrificial electrode is adjacent and substantially parallel to the desired etch window.

3. The method of claim 1 wherein the process further includes the step of feeding back the measured electrical property to a controller performing the etch process.

4. A method of monitoring a through-substrate etching process, comprising the steps of:

providing a sacrificial electrode intersecting a desired etch window;

performing a first etch process on the substrate; and

monitoring the first etch by measuring at least one electrical property of at least one of the sacrificial electrode and the substrate.

5. A method of monitoring a through-substrate etching process, comprising the steps of:

providing a sacrificial electrode intersecting a desired etch window;

performing a first etch process on the substrates

monitoring the first etch by measuring at least one electrical property of at least one of the sacrificial electrode and the substrate,

providing at least one in-situ electrode substantially parallel to the desired etch window;

upon detection of an opening of the sacrificial electrode,

performing a second etch process on the substrate; and

monitoring the second etch by measuring at least one electrical property of the in-situ electrode until a substantial change in the electrical property occurs.

6. A method of monitoring a through-substrate etching process, comprising the steps of:

providing a sacrificial electrode intersecting a desired etch window;

performing a first etch process on the substrate;

monitoring the first etch by measuring at least one electrical property of at least one of the sacrificial electrode and the substrate;

providing at least one in-situ electrode substantially parallel to the desired etch window; and

testing the electrical property of the at least one in-situ electrode to verify that over-etching of the first etch process has not occurred.

7. A method for etching openings within a conductive substrate having a backside, comprising the steps of:

providing at least one sacrificial electrode in proximity to an etch window;

etching the backside of the conductive substrate;

measuring at least one electrical property of the at least one sacrificial electrode and the substrate; and

stopping the step of etching when the measured electrical property triggers a predetermined value.