Method for measuring transistor

• US 8,890,555 B2
• Filed: 04/25/2011
• Issued: 11/18/2014
• Est. Priority Date: 04/28/2010
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Tsuji, Takahiro
• Primary Examiner(s): Vazquez, Arleen M
• Assistant Examiner(s): CURTIS, SEAN M
• Application Number:
  US13/093,172
• Publication Number:
  US 20110267083A1
• Time in Patent Office: 1,303 Days
• Field of Search: 324/750.03, 324/760.01, 324/760.02, 324/762.08
• US Class Current: 324/750.03
• CPC Class Codes: G01R 31/2642 Testing semiconductor operation lifetime or reliability, e.g. by accelerated life tests
• CPC Class Codes: G01R 31/2874 related to temperature
• CPC Class Codes: G01R 31/2886 Features relating to contacting the IC under test, e.g. probe heads; chucks G01R31/2865 takes precedence, test connections, e.g. test sockets, or probes per se, G01R1/04 or G01R1/06
• CPC Class Codes: G01R 31/2891 related to sensing or controlling of force, position, temperature G01R31/2874 takes precedence; sensing of force G01L; sensing of position G01B, G01D; sensing of temperature G01K; controlling in general G05

Abstract

An object is to provide a measuring method with high reproducibility in a bias-temperature stress test of a transistor in which an oxide semiconductor is used for a semiconductor layer. Provided is a measuring method of a transistor, which includes the steps of disposing a transistor in which an oxide semiconductor is used for a semiconductor layer in a measurement room having a light-blocking property, introducing dry air, nitrogen, or argon into the measurement room, and applying a predetermined voltage to a gate electrode of the transistor in the measurement room kept under an atmosphere where the dew point is greater than or equal to −110° C. and less than or equal to −60° C., whereby the amount of change in threshold voltage over time is measured.

Claims

1. A measuring method of a transistor comprising the steps of:

disposing a transistor comprising a semiconductor layer in a measurement room, wherein the semiconductor layer comprises an oxide semiconductor;

introducing one of dry air, nitrogen and argon into the measurement room to make the measurement room of an atmosphere having a dew point of greater than or equal to −

110°

C. and less than or equal to −

30°

C.;

performing a first measurement of a threshold voltage of the transistor in the measurement room kept under the atmosphere;

applying a predetermined voltage to a gate of the transistor in the measurement room kept under the atmosphere after performing the first measurement; and

performing a second measurement of the threshold voltage of the transistor in the measurement room kept under the atmosphere after applying the predetermined voltage to the gate of the transistor.

2. The measuring method according to claim 1, wherein the measurement room has a light-blocking property.

3. The measuring method according to claim 1, wherein the measurement room has a light-blocking property to light having a wavelength of 400 nm or less.

4. The measuring method according to claim 1, wherein the oxide semiconductor is intrinsic or substantially intrinsic.

5. A measuring method of a transistor comprising the steps of:

disposing a transistor comprising a semiconductor layer in a measurement room, wherein the semiconductor layer comprises an oxide semiconductor;

introducing one of dry air, nitrogen and argon into the measurement room to make the measurement room of an atmosphere having a dew point of greater than or equal to −

110°

C. and less than or equal to −

60°

C.;

performing a first measurement of a threshold voltage of the transistor in the measurement room kept under the atmosphere;

applying a predetermined voltage to a gate of the transistor in the measurement room kept under the atmosphere after performing the first measurement; and

performing a second measurement of the threshold voltage of the transistor in the measurement room kept under the atmosphere after applying the predetermined voltage to the gate of the transistor.

6. The measuring method according to claim 5, wherein before introducing the one of dry air, nitrogen and argon into the measurement room, an inside of the measurement room is evacuated.

7. The measuring method according to claim 5, wherein the measurement room has a light-blocking property.

8. The measuring method according to claim 5, wherein the measurement room has a light-blocking property to light having a wavelength of 400 nm or less.

9. The measuring method according to claim 5, wherein the oxide semiconductor is intrinsic or substantially intrinsic.

10. A measuring method of a transistor comprising the steps of:

disposing a transistor comprising a semiconductor layer in a measurement room, wherein the semiconductor layer comprises an oxide semiconductor;

evacuating an inside of the measurement room;

introducing one of dry air, nitrogen and argon into the evacuated measurement room to make the measurement room of an atmosphere having a dew point of greater than or equal to −

110°

C. and less than or equal to −

30°

C.;

performing a first measurement of a threshold voltage of the transistor in the measurement room kept under the atmosphere;

applying a predetermined voltage to a gate of the transistor in the measurement room kept under the atmosphere after performing the first measurement; and

performing a second measurement of the threshold voltage of the transistor in the measurement room kept under the atmosphere after applying the predetermined voltage to the gate of the transistor.

11. The measuring method according to claim 10, wherein the measurement room has a light-blocking property.

12. The measuring method according to claim 10, wherein the measurement room has a light-blocking property to light having a wavelength of 400 nm or less.

13. The measuring method according to claim 10, wherein the oxide semiconductor is intrinsic or substantially intrinsic.