Epitaxial substrate for semiconductor elements, semiconductor element and manufacturing process for epitaxial substrates for semiconductor elements

Abstract

Epitaxial substrate (10) for semiconductor elements (20), containing: a semi-insulating, freestanding substrate (1) formed from Zn-doped GaN, whose dislocation density is less than or equal to 5.0 × 10 7 cm -2 is, a buffer layer (2) adjacent to the freestanding substrate (1); a channel layer (3) adjacent to the buffer layer (2); and a barrier layer (4) provided on the opposite side of the buffer layer (2) with an intervening channel layer (3), wherein the buffer layer (2) made of Al p Ga 1-p N (0.7 ≤ p ≤ 1) is a diffusion-suppressing layer of a thickness of 1 nm to 100 nm and suppresses diffusion of Zn from the freestanding substrate (1) into the channel layer (3) and a concentration of Zn in the channel layer (3) less than or equal to 1×10 16 cm -3 is.

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