AXT, Inc.
LOW ETCH PIT DENSITY 6 INCH SEMI-INSULATING GALLIUM ARSENIDE WAFERS

Abstract:

Methods and systems for low etch pit density 6 inch semi-insulating gallium arsenide wafers may include a semi-insulating gallium arsenide single crystal wafer having a diameter of 6 inches or greater without intentional dopants for reducing dislocation density, an etch pit density of less than 1000 cm.sup.-2, and a resistivity of 1.times.10.sup.7 .OMEGA.-cm or more. The wafer may have an optical absorption of less than 5 cm.sup.-1 less than 4 cm.sup.-1 or less than 3 cm.sup.-1 at 940 nm wavelength. The wafer may have a carrier mobility of 3000 cm.sup.2/V-sec or higher. The wafer may have a thickness of 500 .mu.m or greater. Electronic devices may be formed on a first surface of the wafer. The wafer may have a carrier concentration of 1.1.times.10.sup.7 cm.sup.-3 or less.