Growth of Hexagonal AlN Crystalline Microrod by Physical Vapor Transport Method

doi:10.15541/jim20160250

Abstract

Abstract:

Hexagonal aluminium nitride (AlN) microrods with high crystalline quality were grown by physical vapor transport (PVT) method at low growth temperature between 1700 and 1850℃. The length of as-grown microrod is around 1 cm, and the width between 200-400 μm. The microrod exhibits typical hexagonal geometrical shape with pale yellow color under optical microscopy. Scanning electron microscope (SEM) and atomic force microscope (AFM) images show each microrod with closely arranged step waviness, of which the step interval is 2-4 μm and the height several nanometers. Raman spectrum characterization showed characteristic peaks of high crystalline AlN. The rod-like structure is attributed to slow growth velocity at lower crystalline temperature, enabling Al and N atoms having enough time to move to the lower energy site and to form hexagonal microrod along <0001> direction. High quality hexagonal AlN microrod is an enrichment to one-dimensional semiconductor materials. Data from this study suggest that, by further study on size and impurity control, high performance miniaturized opto-electronic device is hopeful to be achieved.

Key words: III-V semiconductors, aluminum nitride, hexagonal microrod, physical vapor transport

CLC Number:

WANG Hua-Jie, LIU Xue-Chao, KONG Hai-Kuan, XIN Jun, GAO Pan, ZHUO Shi-Yi, SHI Er-Wei. Growth of Hexagonal AlN Crystalline Microrod by Physical Vapor Transport Method[J]. Journal of Inorganic Materials, 2017, 32(2): 215-218.

Figures/Tables 6

Fig. 1 Schematic diagram of PVT growth system for AlN microrod

Fig. 2 Images of AlN microrod(a) Growth on the top raw material; (b) Growth on the bottom of TaC lid; (c - d) Dark-field image taken by optical microscopy

Fig. 3 SEM images of AlN microrod(a) Low magnification image; (b) High magnification image with clear step waviness on the microrod surface

Fig. 4 AFM images of AlN microrod(a, c) AFM surface morphology on the AlN microrod side face; (b, d) Three dimensional AFM image

Table 1 Elemental analysis of AlN microrod measured by EDS

Element	Atomic/at%	Concentration/wt%
C	4.296	2.383
N	36.089	23.342
Al	59.592	74.246
Si	0.023	0.030
Total	100.000	100.000

Fig. 5 Raman spectrum of AlN microrod

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