CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a national phase entry under 35 U.S.C. § 371 of International Application No. PCT/CN2019/080031, filed on Mar. 28, 2019, which claims priority of Chinese patent application No. 201810271475.2, filed with the State Intellectual Property Office of P. R. China on Mar. 29, 2018, the entire contents of both of which are incorporated herein by reference in their entirety.

TECHNICAL FIELD

The present disclosure generally relates to the field of semiconductor processing equipment field and, in particular, to a manufacturing method for an electrostatic chuck and protrusions on the electrostatic chuck.

BACKGROUND

In the semiconductor manufacturing process, an electrostatic chuck (ESC) uses electrostatic adsorption to fix a to-be-processed workpiece, for example, a wafer, to prevent the wafer from moving in the manufacturing process.

The ESC generally includes a dielectric layer carrying the wafer. One or more electrodes are embedded in the dielectric layer. For example, a bipolar electrostatic chuck may include two electrodes, which are electrically connected to positive and negative poles of a DC power supply to provide a DC voltage, respectively. As such, the wafer is firmly attached on the surface of the ESC by electrostatic adsorption.

However, such close contact between the wafer and the ESC may cause friction between the wafer and the ESC to produce small particles. As manufacturing time gradually accumulates, the number of the particles may increase, and a large number of particles may be attached to the back surface of the wafer. Then, the particles may be transferred to different chambers as the process steps progress to negatively impact the semiconductor manufacturing process.

To avoid the above-described situation, a plurality of protrusions at intervals may be formed on the surface of the ESC. As such, the wafer may only contact the ESC through the protrusions on the back surface to reduce the number of the particles attached to the back surface of the wafer. However, the existing protrusions have poor high-temperature resistance and are prone to fall off, thus, they cannot be used in a high-temperature environment.

SUMMARY

For a technical problem in the existing technology, the present disclosure provides an electrostatic chuck (ESC). The ESC includes a support surface for carrying a workpiece and a plurality of protrusions at intervals distributed on the support surface. The protrusions are formed by hydrogen-free amorphous carbon with a resistivity ranging from 10−4Ω·cm to 109Ω·cm.

In particular, a height of a protrusion ranges from 1 μm˜3 μm.

In particular, the ESC further includes an adhesive layer. The adhesive layer includes a plurality of adhesive parts having the same number as the number of the protrusions. Each of the adhesive parts is placed between the support surface and a corresponding one of the protrusions.

In particular, a material of the adhesive layer includes a metal having an adhesive property.

In particular, the metal includes titanium or chromium.

In particular, the ESC further includes a dielectric layer and an electrode provided in the dielectric layer. An upper surface of the dielectric layer is used as the support surface.

The present disclosure further provides a method for manufacturing the protrusions of the ESC, which includes the following processes.

At S1, a patterned mask is formed over the support surface of the ESC for carrying the workpiece.

At S2, a carbon plasma is generated by using a graphite target, and a hydrogen-free amorphous carbon layer is deposited over the support surface of both the area that is covered by the mask and the area that is not covered by the mask.

At S3, the mask is removed to form the plurality of protrusions with the hydrogen-free amorphous carbon having the resistivity ranging from 10−4Ω·cm˜109Ω·cm distributed at intervals over the support surface.

In particular, after the process S1and before the process S2, the method further includes the following processes.

At S12, one or more adhesive layers are deposited over the support surface of both the area that is covered by the mask and the area that is not covered by the mask.

At S2, the graphite target is used to generate the carbon plasma, and the hydrogen-free amorphous carbon layer is deposited over the whole adhesive layer.

At S3, the mask is removed to form the plurality of adhesive parts distributed at intervals over the support surface and the plurality of protrusions each provided at a corresponding one of the plurality of adhesive parts.

In particular, the adhesive layer includes a metal such as titanium or chromium.

In particular, at S2, the process temperature is not higher than 80° C.

In particular, S2further includes the following processes,

At S21, the carbon plasma is generated by using the graphite target.

At S22, when the carbon plasma moves towards the support surface, and the hydrogen-free amorphous carbon layer is deposited over the support surface that is covered by the mask and not covered by the mask, the carbon plasma is filtered and/or focused using a magnetic field.

In particular, the height of the protrusion ranges from 1 μm˜3 μm.

