Silicon carbide substrate, semiconductor device, wiring substrate, and silicon carbide manufacturing method
AssigneesNational University Corporation Tohoku University, Mitsui Engineering & Shipbuilding Co., Ltd.
InventorsTadahiro Ohmi, Akinobu Teramoto, Sumio Sano, Fusao Fujita
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Abstract
A silicon carbide substrate has a high-frequency loss equal to or less than 2.0 dB/mm at 20 GHz is effective to mount and operate electronic components. The silicon carbide substrate is heated at 2000° C. or more to be reduced to the high-frequency loss equal to 2.0 dB/mm or less at 20 GHz. Moreover, manufacturing the silicon carbide substrate by CVD without flowing nitrogen into a heater enables the high-frequency loss to be reduced to 2.0 dB/mm or less.
Claims3
A silicon carbide substrate manufacturing method comprising:
- preparing a preliminary silicon carbide substrate that is formed by chemical vapor deposition (CVD) and that has an RF loss higher than 2 dB/mm at a frequency of 20 GHz, when the RF loss is represented by an operation transmission matrix (S21) of signal passage characteristics;
- and
- heating the preliminary CVDed silicon carbide substrate in a noble gas atmosphere at a temperature between 2000° C. and 2300° C. to reduce the RF loss equal to or less than 2 dB/mm;
- and
- wherein:
- the preliminary CVDed silicon substrate is heated under a nitrogen atmosphere to a temperature lower than 2000° C. and then heated to a temperature between 2000° C. and 2300° C. under the noble gas atmosphere.
Dependencies are inferred from the claim text.