CHARGED PARTICLE BEAM DEVICE

• US 20120112068A1
• Filed: 05/14/2010
• Published: 05/10/2012
• Est. Priority Date: 07/08/2009
• Status: Active Grant

• Current Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.)
• Original Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.)
• Inventors: Ishiguro, Kouji, Maeda, Shusaku
• Granted Patent: US 8,558,193 B2
• Time in Patent Office: Days
• US Class Current: 250/310
• CPC Class Codes: G01B 2210/56 Measuring geometric parameters of semiconductor structures, e.g. profile, critical dimensions or trench depth
• CPC Class Codes: G01N 2223/31 temperature control
• CPC Class Codes: G01N 2223/321 manipulator for positioning a part
• CPC Class Codes: G01N 2223/6116 semiconductor wafer
• CPC Class Codes: G01N 23/2251 using incident electron beams, e.g. scanning electron microscopy [SEM]
• CPC Class Codes: H01J 2237/2001 Maintaining constant desired temperature
• CPC Class Codes: H01J 37/20 Means for supporting or positioning the objects or the material; Means for adjusting diaphragms or lenses associated with the support introducing the objects H01J37/18
• CPC Class Codes: H01J 37/265 Controlling the tube; circuit arrangements adapted to a particular application not otherwise provided, e.g. bright-field-dark-field illumination
• CPC Class Codes: H01J 37/28 with scanning beams H01J37/268, H01J37/292, H01J37/2955 take precedence
• CPC Class Codes: H01J 37/3056 for microworking, e.g. etching of gratings, trimming of electrical components trimming of resistors H01C17/22
• CPC Class Codes: H01L 21/67248 Temperature monitoring

Abstract

The present invention provides a charged particle beam device in which the change of expansion/contraction of a specimen which is an observing object is restricted thereby eliminating position deviation of the observing object and significantly increasing its throughput. The present invention includes specimen holding means for holding a specimen, temperature regulation means which can regulate the temperature of the specimen, and temperature regulation means control means which can control the temperature regulation means based on various conditions.

Claims

1. A charged particle beam device, comprising:

a specimen holding unit for holding a semiconductor wafer;

a specimen stage for moving the specimen holding unit;

a charged beam column having a function to scan a primary charged particle beam onto a semiconductor wafer placed on the specimen stage and to detect generated secondary charged particles to output the same as a secondary charged particle signal; and

an unit for forming an image of the semiconductor wafer from the secondary charged particle signal, wherein

the charged particle beam device further comprises;

a temperature regulation unit for controlling a temperature of the semiconductor wafer, and

a measurement unit for acquiring an observation indication of the wafer that is necessary for controlling the temperature regulation unit in a contactless manner.

2. The charged particle beam device according to claim 1, wherein

the measurement unit is a contactless temperature sensor.

3. The charged particle beam device according to claim 2, wherein

the specimen holding unit is an electrostatic chuck including an electrostatic adsorption plate, and

the temperature sensor is an infrared sensor which is disposed in a through hole formed in the electrostatic adsorption plate.

4. The charged particle beam device according to claim 1 further comprising:

as the measurement unit, an unit for measuring a diameter of the semiconductor wafer.

5. The charged particle beam device according to claim 4, wherein

the charged particle beam device calculates a variation amount of a diameter of the semiconductor wafer from the measured diameter of the wafer, and controls the temperature regulation unit based on the variation amount.

6. The charged particle beam device according to claim 4, wherein

the unit for measuring the diameter of the wafer is a pair of optical displacement sensors disposed on the specimen holding unit.

7. The charged particle beam device according to claim 6, the charged particle beam device further comprising:

an optical height sensor for measuring a height of the wafer, wherein

the pair of optical displacement sensors are disposed in a location where an optical axis of a laser beam that is radiated and detected between the pair of sensors does not overlap an optical axis of a laser beam that is radiated and detected by the optical height sensor on the specimen holding unit.

8. The charged particle beam device according to claim 6, wherein

a laser beam radiated from the optical displacement sensor is turned off in a region on the wafer where an optical axis of the primary charged particle beam crosses an optical path of laser beam irradiated from the optical displacement sensor.

9. The charged particle beam device according to claim 6, wherein

the pair of optical displacement sensors are adapted to radiate and detect two laser beams, and

only one of the two laser beams is turned off in a region where an optical axis of the primary charged particle beam crosses an optical path of a laser beam radiated from the optical displacement sensor.

10. The charged particle beam device according to claim 1, the charged particle beam device further comprising:

as the measurement unit, an information processing unit for performing predetermined processing on pixel data constituting an image of the wafer, wherein

a position deviation at a specific reference position on the wafer is calculated from the pixel data by the information processing unit, and

the temperature regulation unit is controlled by using information of the calculated difference.

11. The charged particle beam device according to claim 10, wherein

the reference position is a position of a defect which is present on the wafer, or an alignment position.

12. The charged particle beam device according to claim 1, wherein

the temperature regulation unit is a Peltier element which is disposed on the specimen holding unit.

13. The charged particle beam device according to claim 12, wherein

the Peltier element is disposed radially from a center of the specimen holding unit to an outer periphery thereof.