Synthesis of bulk polycrystalline indium nitride at subatmospheric pressures
- PDF / 394,710 Bytes
- 7 Pages / 612 x 792 pts (letter) Page_size
- 69 Downloads / 192 Views
MATERIALS RESEARCH
Welcome
Comments
Help
Synthesis of bulk polycrystalline indium nitride at subatmospheric pressures Jeffrey S. Dyck and Kathleen Kasha) Department of Physics, Case Western Reserve University, Cleveland, Ohio 44106-7079
Cliff C. Hayman, Alberto Argoitia,b) Michael T. Grossner, and John C. Angus Department of Chemical Engineering, Case Western Reserve University, Cleveland, Ohio 44106–7217
Wei-Lie Zhouc) Department of Materials Science and Engineering, Case Western Reserve University, Cleveland, Ohio 44106-7204 (Received 10 July 1998; accepted 8 February 1999)
Polycrystalline, wurtzitic indium nitride was synthesized by saturating indium with nitrogen from microwave plasma sources. The structure was confirmed by x-ray diffraction, electron diffraction, and elemental analysis. Two types of growth were observed: (i) dendritic crystals on the original melt surface, and (ii) hexagonal platelets adjacent to the In metal source on the upper edge of the crucible. The method does not involve a foreign substrate to initiate growth and is a potential alternative to the high-pressure techniques normally associated with bulk growth of indium nitride. The lattice parameters were a 3.5366 6 ˚ and c 5.7009 6 0.0005 A, ˚ with cya 1.612 6 0.0005. 0.0005 A
I. INTRODUCTION
II. SYNTHESIS
Indium nitride has received the least attention of the group III nitride semiconductors. The equilibrium vapor pressure of N2 over InN is much higher than that over GaN and AlN, and the In–N bond is the weakest of these nitrides.1,2 While there are currently no applications for pure InN, a significant amount of InN must be incorporated into GaN to obtain blue light emission.3,4 Knowledge of the equilibrium physical properties of pure, bulk InN is critical to understanding these alloy systems. Efforts at bulk synthesis of InN from the elements have primarily been at high pressures because of the high equilibrium pressures of N2 . Synthesis of small crystallites (5–50 mm) has been achieved at N2 pressures of 18–20 kbar over a temperature range of 700–900 ±C.5 We have recently shown that GaN can be synthesized at low pressures by use of atomic nitrogen, N, rather than molecular nitrogen, N2 , to saturate gallium with nitrogen.6–8 Subsequently, we reported the synthesis of InN by the same method.9,10 Krukowski et al. have very recently measured the thermal properties of indium nitride grown by a related method.11 In this paper we report on the growth and characterization of well-faceted, bulk, polycrystalline InN at subatmospheric pressures. Lattice parameters are reported and compared to earlier measurements and calculated values.
In this work synthesis of indium nitride was achieved in both electron cyclotron resonance (ECR) and ball plasma growth chambers. In both reactors synthesis was from In metal and active nitrogen, and was achieved without the aid of a foreign substrate. The apparatus for ECR experiments was described in our earlier work on the synthesis of GaN.6 With the ECR plasma the same growth procedure was u
Data Loading...
