抄録
Preferred orientation of AlN film is changed from (0001) to (101^^-0) by preparation conditions. The reason is explaincd based on extended PBC theory. Any (hkl) planes are made by hypothetical primitive prism units with the height d_<hkl> and the basal plane S_<hkl>. There are some growth units in the prism unit. These growth units have a different attachment energy E_<att> defined as the number of broken bonds of itself. We assume the growth rate (V_<hkl>) is proportional to E_<att>/S_<hkl> of the growth unit having a minimum value or E_<att>, and decreases with in creasing evaporation rate or dissociation rate of the growth unit (dissociation energy: E_<dis>). In AlN crystal, we consider two kinds of growth units: atoms (Al, N) and dimer (Al-N). The preferred orientation of (0001) plane occurs at V_<hkl> ∝E_<att>/n, where n is the number of growth unit with the minimum valuc of E_<att>. The (101^^-0) orientation appears at V_<hkl> ∝E_<dis>, and with the growth unit of Al-N dimer.
