Semi-insulating silicon carbide without vanadium domination

A method of producing a semi-insulating bulk single crystal of silicon carbide, the method comprising:

• heating a silicon carbide source powder in which the amounts of deep level trapping elements in the source powder are below detectable levels to sublimation while,
• heating and then maintaining a silicon carbide seed crystal to a temperature below the temperature of the source powder at which temperature sublimed species from the source powder will condense upon the seed crystal;
• and
• continuing to heat the silicon carbide source powder until a desired amount of single crystal bulk growth has occurred upon the seed crystal;
• and while
• maintaining the source powder and the seed crystal during sublimation growth at respective temperatures high enough to significantly reduce the amount of nitrogen that would otherwise be incorporated into the bulk growth on the seed crystal and to increase the number of point defects in the bulk growth to an amount that renders the resulting silicon carbide bulk single crystal semi-insulating.

A semi-insulating silicon carbide single crystal comprising:

• shallow donor dopants, shallow acceptor dopants, and intrinsic point defects in said silicon carbide single crystal;
• wherein the number of shallow dopants of a first conductivity type is greater than the number of shallow dopants of a second conductivity type;
• and
• the number of intrinsic point defects in said silicon carbide crystal that act to compensate the predominating first type dopant is greater than the numerical difference by which said first type of shallow dopant predominates over said second type of shallow dopant;
• and
• the concentration of elements selected from the group consisting of transition elements and heavy metals is less than the concentration that would affect the electrical properties of the silicon carbide single crystal;
• said silicon carbide single crystal having a resistivity of at least 5000 ohm-cm at room temperature.

A method of producing a high resistivity silicon carbide single crystal substrate comprising:

• irradiating a single crystal of silicon carbide,
• in which the concentration of deep level trapping elements is below the amount that would affect the electrical properties of said silicon carbide single crystal,
• with an irradiating source selected from the group consisting of neutrons, electrons, and gamma radiation, and
• until the number of compensating point defects in the crystal is greater than the net amount of dopant atoms of one conductivity type that predominate over the dopant atoms of the other conductivity type in the crystal.