Electrostatic chuck

• US 6,028,762 A
• Filed: 01/28/1997
• Issued: 02/22/2000
• Est. Priority Date: 01/31/1996
• Status: Expired due to Term

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Corporation
• Inventors: Kamitani, Satoru
• Primary Examiner(s): FLEMING, FRITZ M
• Application Number:
  US08/787,027
• Time in Patent Office: 1,120 Days
• Field of Search: 361/230, 361/233, 361/234, 279/128
• US Class Current: 361/234
• CPC Class Codes: H01L 21/6831 using electrostatic chucks
• CPC Class Codes: H02N 13/00 Clutches or holding devices using electrostatic attraction, e.g. using Johnson-Rahbek effect
• CPC Class Codes: Y10T 279/23 with magnetic or electrostatic means

Abstract

In an electrostatic chunck with grooves formed on the dielectric layer surface, the rate of foreign matter adhering to the semiconductor wafer is reduced and at the same time the semiconduticor wafer can be uniformly heated without causing leakage of lie or other gases supplied to the grooves of the said holding surface into the chamer. The electrostatic chuck is composed of a dielectric layer made from ceramics or sapphire which has electrostatic electrodes, holding surface positioned on a same plane and concave spaces positioned next to the holding surface, at least one of the said holding surface being circumference, and the outermost such holding surface having a width of 1-20 μm and being a smooth surface having a center line average roughness (Ra) of 0.3 μm or less.

Claims

1. In an electrostatic chuck comprising

a rigid dielectric layer made from ceramics or sapphire which has electrostatic electrodes, holding surfaces positioned on a same plane, and at least two grooves adjacent the holding surfaces and having bottom surfaces spaced below plane;

at least two of the holding surfaces being separated by one of the at least two grooves and being formed of concentric rings and adapted to receive generally circular semiconductor wafers of different diameters so that one of the rings is in contact with a semiconductor wafer around a peripheral portion of the wafer adjacent an outer edge thereof when mounted thereon, and each of the rings having a width of 10-20 mm and being a smooth surface having a center line average roughness (Ra) of 0.3 μ

m or less; and

the bottom surfaces of the grooves being spaced at least 5 μ

m below the plane to minimize an amount of foreign-particle adhesion from the bottom surface of the grooves to a semiconductor wafer on the holding surface by electrostatic forces.

2. In an electrostatic chuck comprising

a rigid dielectric layer made from ceramics or sapphire that has electrostatic electrodes, holding surfaces positioned on a same plane, and at least two grooves adjacent the holding surfaces and having bottom surfaces spaced below the plane;

at least two of the holding surfaces being separated by one of the at least two grooves and being formed of concentric rings and adapted to receive generally circular semiconductor wafers of different diameters so that one of the rings is in contact with a semiconductor wafer around a peripheral portion of the wafer adjacent an outer edge thereof when mounted thereon, and each of the rings having a width of 10-20 mm and being a smooth surface having a center line average roughness (Ra) of 0.3 μ

m or less;

the bottom surfaces of the grooves being spaced at least 5 μ

m below the plane to minimize an amount of foreign-particle adhesion from the bottom surface of the grooves to a semiconductor wafer on the holding surface by electrostatic forces;

a source of gas; and

each of the grooves having a through hole for independently feeding gas from the source to the groove.