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The effect of periodic delta-doping and modulation-doping on high Al content n-Al_xGa_(1-x)N(x = 0.55) epilayers grown by MOCVD has been investigated.Measured by XRD,AFM,contactless sheet resistance, and Hall-effect tests,δ-doped and modulation-doped n-Al_xGa_(1-x)N have better crystal quality,surface morphology and electrical properties as compared with uniformly-doped n-Al_xGa_(1-x)N.These improvements are attributed to the SiN_x growth mask induced by 5-doping layers and the dislocation-blocking effect induced by both growth techniques.In addition,due to the broadened doping profile ascribed to enhanced dopant diffusion at high growth temperatures(1150℃) of n-Al_(0.55)Ga_(0.45)N,modulation-doped n-Al_(0.55)Ga_(0.45)N has similar properties asδ-doped n-Al_(0.55)Ga_(0.45)N.
The effect of periodic delta-doping and modulation-doping on high Al content n-Al x Ga 1-x N (x = 0.55) epilayers grown by MOCVD has been investigated. Measured by XRD, AFM, contactless sheet resistance, and Hall- effect tests, δ-doped and modulation-doped n-Al_xGa_ (1-x) N have better crystal quality, surface morphology and electrical properties as compared with uniformly-doped n-Al_xGa_ (1-x) N.These improvements are attributed to the SiN_x growth mask induced by 5-doping layers and the dislocation-blocking effect induced by both growth techniques. In addition, due to the broadened doping profile ascribed to enhanced dopant diffusion at high growth temperatures (1150 ° C) of n-Al_ (0.55 (0.45) N, modulation-doped n-Al_ (0.55) Ga_ (0.45) N has similar properties as δ-doped n-Al_ (0.55) Ga_ (0.45) N.