Active wafer probe

• US 7,427,868 B2
• Filed: 12/21/2004
• Issued: 09/23/2008
• Est. Priority Date: 12/24/2003
• Status: Expired due to Fees

• Current Assignee: FormFactor Beaverton, Inc. (FormFactor Incorporated)
• Original Assignee: Cascade Microtech Incorporated (FormFactor Incorporated)
• Inventors: Gleason, K. Reed, Strid, Eric
• Primary Examiner(s): TANG, MINH NHUT
• Application Number:
  US11/019,440
• Publication Number:
  US 20050140386A1
• Time in Patent Office: 1,372 Days
• Field of Search: None
• US Class Current: 324/755.03
• CPC Class Codes: G01R 1/06711 Probe needles; Cantilever beams; "Bump" contacts; Replaceable probe pins
• CPC Class Codes: G01R 1/06766 Input circuits therefor
• CPC Class Codes: G01R 1/06772 High frequency probes

Abstract

A probe suitable for probing a semiconductor wafer that includes an active circuit. The probe may have a rigid probing member and include a flexible interconnection between the active circuit and a support structure. The active circuit may have a relatively low capacitance as seen by the device under test.

Claims

1. A probe for testing a device under test comprising:

(a) an elongate probing element;

(b) an active circuit having an input with a first impedance, of more than 1,000 ohms and less than 1,000 fF, electrically interconnected to said probing element and a second input;

(c) a flexible structure interconnecting said active circuit and a supporting structure, such that said flexible structure is the primarily supporting structure between said active circuit and said supporting structure, such that when said probing element comes into contact with said device under test said flexible structure flexes;

(d) a transmission structure electrically interconnected to said second input.

2. The probe of claim 1 wherein said first impedance has a resistance greater than 500 K Ohms.

3. The probe of claim 1 wherein said first impedance has a resistance greater than 1,000 K Ohms.

4. The probe of claim 1 wherein said first impedance has a capacitance less than 25 fF.

5. The probe of claim 1 wherein said supporting structure includes said transmission structure and said flexible structure includes the same class of transmission structure.