Eliminating inline positional errors for four-point resistance measurement

• US 7,944,222 B2
• Filed: 11/08/2010
• Issued: 05/17/2011
• Est. Priority Date: 10/17/2005
• Status: Active Grant

• Current Assignee: CAPRES A/S (KLA Corporation)
• Original Assignee: CAPRES A/S (KLA Corporation)
• Inventors: Hansen, Torben M.
• Primary Examiner(s): Nguyen; Vincent Q
• Application Number:
  US12/941,929
• Publication Number:
  US 20110084706A1
• Time in Patent Office: 190 Days
• Field of Search: 324/713, 324/715
• US Class Current: 324/715
• CPC Class Codes: G01R 27/08 Measuring resistance by measuring both voltage and current

Abstract

Calculating resistance correction factors includes contacting the arms of a four-arm probe with a test sample; selecting a first set of first and second arms and a second set of third and fourth arms; applying a first current from the first arm to the second arm of the first set; detecting a first voltage between the third and fourth arms of the second set; calculating a first resistance using the first voltage and current; selecting a third set of first and second arms including no more than one arm of the first set, and a fourth set of third and fourth arms including no more than one arm of the second set; applying a second current from the first arm to the second arm of the third set; detecting a second voltage between the third and fourth arms of the fourth set; calculating a second resistance using the second voltage and current; and calculating a correction factor using the first and second resistances.

Claims

1. A method for obtaining a characteristic electrical property of a test sample by using a probe having a body and at least four probe arms each including a probe tip, said characteristic electrical property including a resistance property, said probe arms extending parallel from said body, said probe including electrical contact points for establishing electrical contact between said probe tips and a test apparatus operable for transmitting and receiving electrical signals to and from said probe tips, said method comprising the following steps:

(a) positioning said probe tips in contact with a surface of a test sample,

(b) selecting a subset of four probe tips for performing a measurement by applying a current between a first set of two probe tips and determining a voltage between a second set of two probe tips not including any of the probe tips of said first set, and performing said measurement for all combinations of sets of probe tips,

(c) establishing a model value of said characteristic electrical property,

(d) calculating model data for said characteristic electrical property based on said model value,

(e) if said measurement and said calculated model data do not converge, establishing an adjusted model value and repeating step (d) using said adjusted model value, and

(f) if said measurement and said calculated model data do converge, extracting said characteristic electrical property from said model data.

2. The method according to claim 1, wherein said step (b) further comprises calculating a corrected value of one of said measurements.

3. The method according to claim 1, wherein said characteristic electrical property is selected from the group consisting of top-layer resistance, bottom-layer resistance, resistance-area product, and any combination thereof.

4. The method according to claim 1, wherein said model data is calculated using the formula

5. The method according to claim 1, wherein said method further includes performing a correction on one of said calculated model data.