Active wafer probe

• US 7,759,953 B2
• Filed: 08/14/2008
• Issued: 07/20/2010
• Est. Priority Date: 12/24/2003
• Status: Expired due to Fees

• Current Assignee: Cascade Microtech Incorporated (FormFactor Incorporated)
• Original Assignee: Cascade Microtech Incorporated (FormFactor Incorporated)
• Inventors: Gleason, K. Reed, Strid, Eric
• Primary Examiner(s): Tang; Minh N
• Application Number:
  US12/228,812
• Publication Number:
  US 20080309358A1
• Time in Patent Office: 705 Days
• Field of Search: None
• US Class Current: 324/762.05
• 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 include a flexible interconnection between the active circuit and a support structure. The probe may impose a relatively low capacitance on the device under test.

Claims

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

(a) an elongate tapered 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 when said probing element comes into contact with said device under test said flexible structure flexes and said active circuit moves relative to said supporting structure before said probing element is substantially deflected;

(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.