Wafer actually refers to the silicon wafer used to make silicon semiconductor circuits; diamond wafer is a thin sheet made of single crystal diamond C. Diamond has good physical and chemical properties and excellent semiconductor electrical properties, and has excellent properties such as high hardness, high thermal conductivity, and high chemical stability, so it is known as the "ultimate semiconductor material."

1. Development prospects of diamond wafers

With the rapid development of new energy vehicles, high-speed trains, the Internet of Things, 5G technology, artificial intelligence and other technologies, the demand for high-efficiency and high-performance semiconductor devices and integrated circuits continues to increase, and the research and application fields of diamond wafers continue to expand. Diamond wafers have broad application prospects in semiconductors, optoelectronics, biomedicine and other fields, and are expected to become an important support for future high-tech industries.

The main reason for the restriction of the development of the diamond wafer industry is that the size of wafers made of diamond is too small to meet the needs of semiconductor use. Therefore, how to realize the production and manufacturing of large-size diamond wafers has become a difficult problem that the semiconductor industry urgently needs to break through.

2. Application scope of diamond wafer

Diamond wafer has a wide range of applications in semiconductors, optoelectronics, biomedicine and other fields. In addition, diamond wafer can also be used in the following fields:

• Microwave devices

• High temperature/high power/high frequency electronic devices

• Optoelectronic devices

• Biosensors

• Optoelectronic devices

• Aerospace

......

3. Diamond wafer inspection requirements

The inspection requirements of diamond wafers mainly include surface roughness, flatness, defect detection, thickness and size. In order to ensure the quality and performance of the product, it needs to be fully inspected and analyzed.

• Flatness/flatness

The insufficient flatness of diamond wafers will cause changes in the thermal stress of the packaging process, thus affecting the reliability of the product. Therefore, it is necessary to detect the flatness/flatness of diamond wafers to improve the processing technology and reduce customer complaints.

• Surface roughness

The surface roughness of diamond wafers affects the heat dissipation and mounting effects of products. As a third-generation (wide bandgap) semiconductor material with excellent performance and a new type of thermal management material, diamond has ultra-high thermal conductivity, so it has great potential in heat dissipation, and the surface roughness of diamond wafers affects the heat dissipation performance of wafers. If the surface roughness of diamond wafers is too large, it will affect the mounting effect of wafers. In addition, the surface roughness of diamond wafers also affects the performance and reliability of chips, so it is necessary to measure the surface roughness to ensure that the surface roughness is within a certain range, optimize the processing technology, and effectively reduce the surface roughness.

4. Diamond wafer inspection case

A company hopes to improve product quality and performance and reduce customer complaints by inspecting the surface roughness and flatness of diamond wafers. After receiving the measurement requirements, Atometrics selected the white light interferometer ER230 for inspection. The inspection results of some samples are as follows:

Sample 1: Roughness measurement

Sample 2: Grinding Texture

Sample 3: Rougness and flatness measurement

After receiving the test report, the customer said: "In terms of roughness and flatness testing of diamond wafers, we have evaluated many measuring instruments, including some international brands. Their testing results are also very good, but the price is too high. We did not expect that today's Chinese equipment can also achieve such high-precision 3D shape measurement, and the key is that the cost performance is so high. This equipment is of great help to our product upgrade!"

The AM-7000 series of Atometrics white light interferometers have sub-nanometer accuracy.

The highest RMS repeatability can reach 0.002nm, and with a large range of piezoelectric ceramic devices, the maximum scanning speed is 400μm/second.

3200Hz plus the industry's first SST+GAT algorithm can instantly complete up to 5 million point cloud acquisition.

The white light interferometer is based on the principle of white light interference. Through optical interference phase measurement, the detection accuracy of less than 1nm can be obtained at any magnification.

Covering the commonly used international standard measurement tools on the market, it can easily analyze 3D data with high efficiency and can easily cope with applications in various industries.

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