Infineon ‘cold-split’ SiC ready for production
Infineon contends the technique will provide a competitive advantage for the company in the production of silicon-carbide power semiconductors.
Infineon acquired a local startup Siltectra GmbH for €124 million (about US$140 million) in November 2018 for its so-called cold-split wafer production technology (see Infineon buys Siltectra to boost silicon carbide production).
Meanwhile Soitec, which has used wafer splitting in the production of silicon-on-insulator wafers for many years, has teamed up with Applied Materials to apply the process to silicon-carbide (see Project to improve silicon carbide wafer substrates).
Now Infineon CEO Reinhard Ploss, has said that the technology has been developed further. “Today we can announce: The first product based on cold split technology has been qualified for production. We are now ramping up a pilot line and preparing for volume production.”
For now Infineon is using cold-split to separate thin wafers from the silicon-carbide boule. Conventionally such wafers are produced by sawing slices and then using chemical mechanical polishing to produce smooth surfaces. However, about half the volume of the boule is lost during sawing and another quarter during the polishing.
Infineon’s cold-split – analogous to splitting slates from rock – reduces the loss of raw material by half compared to the conventional sawing process, providing a competitive advantage.
Infineon wants to develop the cold-split technology further and use it to split processed wafers and lift a 100-micron layer of active devices off the wafer. This would allow the revealed surface to be processed and further improve costs.
Ploss called this “making two out of one” and said it would provide a sustainable competitive advantage for Infineon. It appears the process could be taken further to make more than two wafers from the initial one cut from the boule.
The Soitec SmartCut on SiC pilot line was expected to start producton in 1H20.
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