Wafer polishing device based on inductively coupled plasma

Abstract

The invention relates to a wafer polishing device based on inductively coupled plasma. The device comprises a plasma torch, an electric spark igniter, a coil and a numerical control platform, the plasma torch comprises three coaxially-arranged generating tubes, and the numerical control platform is used for placing a wafer to be polished; and the removal amount distribution of the plasma torch is calculated according to the temperature distribution of the plasma torch, plasma processing errors are compensated through a processing path optimization algorithm to obtain a scanning path, and the wafer to be polished is controlled to be irradiated by the inductively coupled plasma formed under the scanning path. According to the device, high-efficiency and high-precision polishing of the large-size single crystal gallium nitride wafer can be realized.

Description

technical field [0001] The invention relates to the technical field of wafer polishing, in particular to a wafer polishing device based on inductively coupled plasma. Background technique [0002] Gallium nitride is a third-generation semiconductor material with broad application prospects. It has excellent physical and chemical properties and is widely used in the manufacture of electronic devices and optoelectronic devices. Polishing is the last process in the manufacture of GaN wafers, and the quality of GaN wafers directly determines the performance of GaN-based devices. Common polishing methods for GaN wafers include mechanical polishing, chemical mechanical polishing, and photoelectrochemical assisted polishing. [0003] Mechanical polishing uses abrasive grains with high hardness to remove the surface material by plastic deformation through the scraping between the abrasive grains and the surface of the material. This method has a high material removal rate, but int...

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Problems solved by technology

[0004] However, many of the aforementioned methods for polishing gallium nitride wafers have certain shortcomings and are difficult to continue to promote:

[0005] 1. Traditional mechanical polishing and chemical mechanical polishing methods cannot take into account high polishing efficiency and good surface roughness, and it is difficult to obtain satisfactory surface quality

[0006] 2. Photoelectrochemical assisted polishing needs to consume a large amount of electrolyte solution, and the experimental equipment is relatively complicated and easy to corrode

At the same time, the direct discharge of waste liquid will pollute the environment, requiring multiple post-processing procedures, and the post-treatment process of waste liquid also requires high costs.

[0007] 3. Chlorine / argon-based vacuum induction plasma uses toxic and harmful gases such as chlorine, which endangers the personal safety of operators

In addition, the exhaust gas needs to be discharged through a treatment device, and the cost of use is high; although the material removal rate reaches 240 nanometers per minute, it cannot achieve a nano-scale smooth surface and cannot meet the growing needs of the gallium nitride wafer industry; and the The technology needs to be carried out under vacuum conditions, and a series of devices such as vacuum chambers are required, which is expensive

In summary, this method cannot achieve high-efficiency and high-precision polishing of large-size single-crystal GaN wafers.

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