AES Semigas


15 December 2022

Disco develops fully automatic grinder for 100-200mm Si and SiC wafers

At SEMICON Japan 2022 at Tokyo Big Sight (14-16 December), Tokyo-based equipment maker DISCO Corp – which makes semiconductor manufacturing equipment including chemical mechanical polishing (CMP) systems and laser-based ingot slicing equipment and processes – is exhibiting the new DFG8541, a fully automatic grinder that can process silicon (Si) and silicon carbide (SiC) wafers up to a maximum diameter of 8-inches (100-200mm).

For grinding wafers smaller than 8-inches, DISCO has been providing the fully automatic grinder DFG8540, which has been shipped to many device manufacturers and electric component manufacturers as a standard dual-axis grinder. However, two decades have passed since the initial release of DFG8540, and customers’ processing targets have expanded from not only silicon but also to compound semiconductors including SiC. In addition, with growing needs for wafer thinning along with the development of high-density packaging technologies, maintaining higher cleanliness inside the equipment is now required in order to reduce breakage risks caused by the adherence of particles during processing, transferring and cleaning.

DISCO has hence developed the successor, DFG8541, aiming for stable thinning while maintaining high cleanliness as well as improved operability and productivity. By making a high-torque spindle an option, it is possible to support difficult-to-process materials that have high rigidity such as SiC, responding to the needs of SiC power semiconductor manufacturing that have been growing due to the global trend toward decarbonization.

The new DFG8541 is said to prevent the adherence of particles inside the equipment and reduce the breakage risk of thin wafers by adopting a non-contact wafer-centering mechanism that uses a camera, and adopting atomizing nozzle cleaning as standard functions for the chuck table; processed wafers on the chuck table; spinner table; and processed wafers on the spinner table.

For improved operability and productivity, the installed monitor size has been expanded from 15-inches (DFG8540) to 19-inches (using a capacitive touch panel). As recipes can be set for each wafer, continuous processing can be performed even when multiple recipes are present. The DFG8541 can support multi-variety low-volume production. Also, by installing an electric axis for chuck table inclination adjustment, the processing shape can be corrected by inputting the value on the monitor screen, reducing the downtime for adjustment.

Regarding wafer protection functions, the DFG8541 reduces the risk of breakage of high-cost wafers such as developmental products, cutting-edge products, and SiC. Also, a wafer mapping function detects cross-slotted wafers in the cassette using a sensor. A pre-processing wafer thickness detection function detects thickness irregularities such as the attachment of multiple surface protection tapes in advance. A vacuum retention function sends an alert when a power outage occurs during wafer transfer.

By adopting a built-in vacuum pump, the footprint has been reduced by 15% compared with that of DFG8540. Also, by adopting a new bearing structure, air consumption is reduced by about 50%. The DFG8541 hence contributes to energy saving in plant facilities (compressors).

Sales of the DFG8541 are scheduled to commence in June 2023.

Tags: SiC substrates


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