TY - JOUR
T1 - Trade-off between thickness and temperature ramping rate of GaN buffer layer studied for high quality GaN growth on GaAs (1 1 1)A substrate
AU - Murakami, Hisashi
AU - Kangawa, Yoshihiro
AU - Kumagai, Yoshinao
AU - Koukitu, Akinori
N1 - Funding Information:
This work was partly supported by the 21st Century Center of Excellence (COE) program of “Future Nano-Materials” research and education project at Tokyo University of Agriculture & Technology, which is financially supported by the Ministry of Education, Culture, Sports, Science and Technology. H. Murakami is financially supported by a Grant-in-Aid for JSPS Fellows, which is financially supported by the Ministry of Education, Culture, Sports, Science and Technology.
PY - 2004/7/15
Y1 - 2004/7/15
N2 - The correlation between crystallization of low-temperature (LT) GaN buffer layer and crystalline quality of subsequently grown thick GaN layer at high-temperature on GaAs (111)A substrate has been investigated. During heating of LT-GaN buffer layer to 1000°C, the degree of crystallization highly depended on the thickness and the temperature ramping rate of GaN buffer layers. When the LT-GaN buffer layer was less than 40-nm-thick or temperature ramping rate was low, excess crystallization and/or agglomeration of the buffer layer occurred, which resulted in a poor crystalline quality of the GaN epitaxial layer subsequently grown on it. On the other hand, when the thickness of LT-GaN buffer layer exceeded 100nm, there was relatively little agglomeration of buffer layer, which also resulted in poor crystalline quality of the subsequently grown GaN. To grow high-quality GaN layer at high-temperature, optimum crystallization condition for GaN buffer layer just prior to high-temperature growth was found to be as follows: single crystallites region in the GaN buffer layer occupied a volume 40% as large as the randomly aligned matrix. The trade-off between thickness and temperature ramping rate of GaN buffer layer clearly indicates that the degree of crystallization of the GaN buffer layer is an important parameter for achieving high-quality GaN growth at high-temperature.
AB - The correlation between crystallization of low-temperature (LT) GaN buffer layer and crystalline quality of subsequently grown thick GaN layer at high-temperature on GaAs (111)A substrate has been investigated. During heating of LT-GaN buffer layer to 1000°C, the degree of crystallization highly depended on the thickness and the temperature ramping rate of GaN buffer layers. When the LT-GaN buffer layer was less than 40-nm-thick or temperature ramping rate was low, excess crystallization and/or agglomeration of the buffer layer occurred, which resulted in a poor crystalline quality of the GaN epitaxial layer subsequently grown on it. On the other hand, when the thickness of LT-GaN buffer layer exceeded 100nm, there was relatively little agglomeration of buffer layer, which also resulted in poor crystalline quality of the subsequently grown GaN. To grow high-quality GaN layer at high-temperature, optimum crystallization condition for GaN buffer layer just prior to high-temperature growth was found to be as follows: single crystallites region in the GaN buffer layer occupied a volume 40% as large as the randomly aligned matrix. The trade-off between thickness and temperature ramping rate of GaN buffer layer clearly indicates that the degree of crystallization of the GaN buffer layer is an important parameter for achieving high-quality GaN growth at high-temperature.
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U2 - 10.1016/j.jcrysgro.2004.04.107
DO - 10.1016/j.jcrysgro.2004.04.107
M3 - Article
AN - SCOPUS:2942729974
VL - 268
SP - 1
EP - 7
JO - Journal of Crystal Growth
JF - Journal of Crystal Growth
SN - 0022-0248
IS - 1-2
ER -