Low resistivity of highly Si-doped n-type Al_0.62Ga_0.38N layer by suppressing self-compensation

Highly Conductive n-Al0.65Ga0.35N Grown by MOCVD Using Low V/III Ratio

“…We have recently demonstrated that the self-compensation behavior of Al 0.65 Ga 0.35 N has a strong dependence on growth temperature and growth rate [14], which is in agreement with recent theoretical [15] and experimental reports [12,[16][17][18]. In this work, we show that the V/III ratio during MOCVD growth has a similarly important effect.…”

“…Some early reports found knee behavior above [Si] ≈2 × 10 18 cm −3 (x = 0.6) [27] or as low as 4 × 10 17 cm −3 (x = 0.54) [11]. Decreased growth temperature and V/III ratio both lead to less abrupt knee characteristics with higher threshold [Si] values, with recent reports confirming successful [Si] doping above 10 19 cm −3 via optimized growth conditions [12,[14][15][16][17][18]. Extrinsic impurities can be ruled out as the major compensating defects in heavily doped AlGaN:Si using SIMS [10][11][12]14,27].…”

Regulation of surface kinetics: rapid growth of n-AlGaN with high conductivity for deep-ultraviolet light emitters

“…It is noted that the electron concentration in n-AlGaN here (grown at 1050 °C) is obviously higher than that in a referential Al 0.55 -Ga 0.45 N epilayer grown at 1100 °C (9.27 × 10 18 cm −3 ), which is attributed to the suppression of V III -Si at a lower growth temperature. 7,10 The high electron concentration can ensure the ohmic contact even after etching as shown in Fig. 4(b).…”

“…In terms of the electron concentration and conductivity, group-III-vacancy-Si complexes (V III -Si) and carbon on nitrogen sites (C N ) have been demonstrated as the dominant compensation defects in n-AlGaN. 6,7 In order to suppress the formation of both defects, the growth temperature is optimized, and an appropriate range of 1040-1080 °C is generally adopted. [7][8][9][10] However, such a low temperature is unfavorable for the two-dimensional growth of Al-rich AlGaN, hence the growth rate is limited to obtain a smooth surface.…”

“…6,7 In order to suppress the formation of both defects, the growth temperature is optimized, and an appropriate range of 1040-1080 °C is generally adopted. [7][8][9][10] However, such a low temperature is unfavorable for the two-dimensional growth of Al-rich AlGaN, hence the growth rate is limited to obtain a smooth surface. 11,12 On conventional sapphire with a miscut angle of 0.2°, the upper-bound growth rate for the two-dimensional growth of Al 0.65 Ga 0.35 N is experimentally determined to be around 0.65 μm h −1 at 1100 °C.…”