Proposed casting method is relatively simple and shorter, making it suitable for automated control and aiding future production.
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第四代半导体突破还是吹牛?
A team from Zhejiang University has made strides using a self-developed approach. Led by Yang Deren, a member of the Chinese Academy of Sciences and director of Zhejiang University’s State Key Laboratory of Silicon Materials, the team produced 4-inch wafers in August, improving on their 2-inch wafers from May last year. Moreover, their process is more simple, controllable and cost effective.
Zhang found that for third generation and beyond wide band gap semiconductor materials, most are synthesised through vapour-phase methods. In contrast, gallium oxide is the only material that can form single crystals by solidifying from a melt at standard atmospheric pressure, helping to cut fabrication costs and thus aid mass production. “In Japan and America, a modelling method is commonly used. However, this method requires a large amount of iridium to make the crucible. Typically, a 4-inch gallium oxide crucible would need at least 5kg [11lbs] of iridium,” he said.
“Given that the price of iridium is almost three times that of gold, the method significantly increases the cost of gallium oxide. Moreover, a foreign method could potentially lead to international intellectual property disputes,” Zhang said.