Bonding Technology Overview

Through polishing monocrystalline and polycrystalline SiC substrates, bonding them after ion doping and then thermally splitting them, we form a thin monocrystalline layer on top of a polycrystalline substrate.

Phenomena Characteristic to Direct Bonded Substrate

As we manufacture with a bonding process, there may be minute voids and untransferred faults (layer transfer failures) in the substrates. (See standard specifications for the guaranteed number.) Untransferred faults are killer faults as the part of these faults have no monocrystalline layer.

As in the table to the right, we measure the static characteristics of the 650V-SBD (JBS) chip and investigate the relationship between the quality characteristics of direct bonded substrates and device yield. We see no correlation between voids and SBD device yield, and we believe that the effect that voids have on device characteristics is small.

Additionally, while there may be concerns about the transferred layer peeling off, there is no variation between the monocrystalline and polycrystalline thermal expansion coefficient as shown in the graph to the right, so there will be no peeling due to thermal expansion difference.

Click here for standard specifications of products

Click here for standard
specifications of products