JP2011233932A5

JP2011233932A5 -

Info

Publication number: JP2011233932A5
Application number: JP2011173502A
Authority: JP
Filing date: 2011-08-09
Publication date: 2012-03-01
Anticipated expiration: 2026-08-23

Claims

Providing a 4H silicon carbide single crystal substrate having an offset angle of 2 ° to 10 °;
Growing an epitaxial layer made of silicon carbide on the silicon carbide single crystal substrate at a temperature of 1400 ° C. or higher and 1650 ° C. or lower by a chemical vapor deposition method;
Heat treating the epitaxial layer at a temperature of 1300 ° C. or higher and 1800 ° C. or lower;
Including
In the step of growing the epitaxial layer, the ratio C / Si for the silicon atoms of the carbon atoms in the raw material gas is Ri der 1.5 to 2,
A method for manufacturing a silicon carbide semiconductor epitaxial substrate, wherein the step of growing the epitaxial layer is performed at a pressure of 3 kPa to 54 kPa .

The epitaxial layer grown in the step of growing the epitaxial layer is a level whose activation energy difference ΔEa from the lower end of the conduction band of the silicon carbide semiconductor is 1.33 ev or more and 1.53 eV or less in deep level transient spectroscopy. The method for manufacturing a silicon carbide semiconductor epitaxial substrate according to claim 1, wherein the peak is observed separately from the peak of the point defect EH _6/7 center.

In the step of growing the epitaxial layer, the density of the point defect Z _1/2 center in the epitaxial layer is 1 × 10 ¹² cm ⁻³ or less, and the density of the point defect EH _6/7 center is 5 × 10 ¹¹ cm. ^The method for manufacturing a silicon carbide semiconductor epitaxial substrate according to claim 1, wherein the epitaxial layer is grown under a growth condition of ⁻³ or less.

In the step of growing the epitaxial layer, the density of point defects having an activation energy difference ΔEa from the lower end of the conduction band of the silicon carbide semiconductor of 1.33 ev to 1.53 eV is 3 in the epitaxial layer. The method for manufacturing a silicon carbide semiconductor epitaxial substrate according to claim 3, wherein the epitaxial layer is grown under a growth condition of × 10 ¹¹ cm ⁻³ or more.

The step of heat-treating the epitaxial layer is performed under a condition that the density of point defects having a level of ΔEa of 1.33 ev or more and 1.53 eV or less in the epitaxial layer is ½ or less before the heat treatment. The method for manufacturing a silicon carbide semiconductor epitaxial substrate according to claim 1, wherein the epitaxial layer is heat-treated.

The step of heat-treating the epitaxial layer is performed under the condition that the density of point defects having a level of 1.33 ev or more and 1.53 eV or less in the epitaxial layer is 3 × 10 ¹¹ cm ⁻³ or less. The manufacturing method of the silicon carbide semiconductor epitaxial substrate of Claim 5 which heat-processes.

The method for manufacturing a silicon carbide semiconductor epitaxial substrate according to claim 1, wherein the epitaxial layer is grown at a speed of 10 μm / h or more and 23 μm / h or less.