Large Diameter, High Quality SiC Single Crystals, Method and Apparatus

A SiC sublimation crystal growth system comprising;

• a growth crucible configured to be charged with SiC source material and a SiC seed crystal in spaced relation;
• and
• a separation plate separating the growth crucible into a source compartment where the SiC source material resides when the growth crucible is charged with the SiC source material and a crystallization compartment where the SiC seed crystal resides when the growth crucible is charged with the SiC seed crystal, wherein:
• the separation plate includes a first, central part surrounded by a second part that has a lower permeability to SiC bearing vapors originating from the SiC source material during sublimation growth of a SiC crystal on the SiC seed crystal than the first, central part;
• and
• a ratio of mass transport of the SiC bearing vapors through the inner part of the separation plate versus mass transport of the SiC bearing vapors through the outer part of the separation plate is no less that about 50/1.

A method of forming a high-quality SiC single crystal wafer comprising:

• sublimation growing on a SiC single crystal seed a SiC single crystal boule having a diameter sufficient for slicing wafers between 100 and 200 mm in diameter, wherein said sublimation growth occurs in the presence of controlled axial and radial temperature gradients and controlled flux of sublimated source material;
• and
• slicing from said SiC boule a SiC wafer having:
• a diameter between 100 and 200 mm inclusive;
• a lattice curvature of no more than about 0.2°, 0.1°, or 0.06° over the total area of the wafer;
• and
• a full width at half maximum (FWHM) of the x-ray reflection of no more than about 50, 30, or 20 arc-seconds over the total area of the wafer.

A high-quality SiC single crystal wafer having a diameter between 100 and 200 mm and comprising at least one of the following:

• a lattice curvature of no more than about 0.2°, 0.1°, or 0.06° over the total area of the wafer;
• or
• a full width at half maximum (FWHM) of the x-ray reflection of no more than about 50, 30, or 20 arc-seconds over the total area of the wafer;
• or
• a combined area of stacking faults no more than about 5%, 2%, or 1% of a total area of the wafer.