Processing products and technical background
A semiconductor equipment manufacturer recently launched a localization project for silicon carbide spray plates, which requires processing two types of array microholes of D0.5×6.5mm (depth-to-diameter ratio 13:1) and D1×6.5mm on a silicon carbide substrate with a hardness of HV2,700. As the core component of the third-generation semiconductor etching equipment, this component has long been dependent on imports. Its processing accuracy directly affects the chip manufacturing yield, and the chipping control and depth-to-diameter ratio breakthrough in microhole processing have become the key bottlenecks for domestic substitution.
Industry processing pain points
Traditional processing solutions face three challenges:
First, the hardness of silicon carbide is close to that of diamond, and ordinary drill bits can only process 3-5 holes before they are worn out;
Second, the 13:1 depth-to-diameter ratio makes it difficult to remove chips, which can easily cause scratches on the hole wall or even drill bit breakage;
Third, the cost of imported OEM is as high as 28,000 yuan per piece, and the delivery cycle is as long as 6 months, which seriously restricts the security of the domestic semiconductor equipment supply chain.
MID solutions
In view of the ultra-hard and brittle characteristics of silicon carbide, the MID R&D team innovatively adopted the "ultrasonic vibration + integral PCD drill" composite process:
The 20kHz ultrasonic high-frequency vibration reduces the cutting resistance by 45%, and cooperates with the independently designed PCD (polycrystalline diamond) drill to achieve continuous and stable processing of 102 D0.5mm microholes, and the life of a single drill bit is increased by 20 times
Using the ultrasonic cavitation effect to enhance the penetration of coolant, the hole mouth chipping is controlled within 0.018mm, which is better than the industry standard of 0.03mm
The original spiral chip removal path design ensures that the hole wall roughness Ra≤0.4μm of the 13:1 depth-to-diameter ratio microhole meets the semiconductor-level cleanliness requirements
Technical breakthrough value
This processing verification has achieved two major milestones: for the first time, the processing cost of domestic silicon carbide spray plate microholes has been reduced to 1/3 of the import price, and the delivery cycle has been compressed to 15 days; more breakthrough, the depth-to-diameter ratio processing limit has been increased from the industry's common 8:1 to 13:1, providing independent and controllable parts guarantee for advanced process chip equipment below 5nm.
