Ring member for holding wafer

Abstract

In a CMP device for polishing a surface of a wafer, this ring member for holding the wafer is provided on the outer circumferential side of the wafer to hold the wafer and is to be polished together with the wafer. The ring member for holding the wafer is characterized by being configured from a silicon material containing one or two types of doping elements selected from B and Ga in a total amount in the range of 1.0 x 10-5 g / cm3 to 5.0 x 10-3 g / cm3 inclusive, and having specific resistivity in the range of 1 x 10-4 to 1 x 10-1 Ω･cm inclusive.

Claims

1. In a CMP apparatus for polishing the surface of a wafer, a wafer holding ring member is disposed on the outer periphery of the wafer, holds the wafer, and is polished together with the wafer, wherein one or two doping elements of B and Ga total 1.0 × 10 －５ g / cm ３ The above 5.0 x 10 －３ g / cm ３ It is composed of silicon materials that fall within the following range, with a resistivity of 1 × 10⁻⁶. －４ Ω・cm or more 1×10 －１ A wafer-holding ring member characterized by being within the range of Ω·cm or less.

2. The content of B contained as the doping element in the silicon material is 2.5×10 －５ g / cm ３ or more and 2.7×10 －３ g / cm ３ or less, and the wafer holding ring member according to claim 1 is characterized in that it is within the following range.

3. The silicon material further contains one or more elements selected from P, As, and Sb as secondary doping elements totaling 1.0 × 10⁻¹⁶ －８ g / cm ３ The above 5.0 x 10 －６ g / cm ３ A wafer holding ring member according to claim 1 or 2, characterized in that it includes the following within the range.

4. The total content of Cr, Fe, and Ni in the silicon material is 1 × 10 ―１０ atom / cm ３ The wafer holding ring member according to claim 1 or 2, characterized in that it is as follows.

5. The oxygen concentration in the silicon material is 1 × 10 １７ atom / cm ３ The above 5 x 10 １７ atom / cm ３ The wafer holding ring member according to claim 1 or 2, characterized in that it is within the following range.

6. The wafer holding ring member according to claim 1 or 2, characterized in that it has a bending strength of 82 MPa or more.

7. A wafer holding ring member according to claim 1 or 2, characterized in that it is made of columnar crystalline silicon.

8. The wafer holding ring member according to claim 1 or 2, characterized in that it has a screw insertion hole through which a screw is inserted.

Images