Microstructure evolution of AlN films deposited under various pressures by RF reactive sputtering

Wurtzite AIN (2H-AIN) films were deposited on p-type Si(100) by RF planar maanetron reactive sputtering under various pressures at a relatively low temperature (350 degreesC). X-Ray diffraction (XRD) and selected area electron diffraction (SAD) were used to study the microstructural features of the deposited films. XRD results showed that with the decrease in sputtering gas pressure, the preferred orientation of AIN films changed from (100) to (002). SAD results confirmed that a strong (100) texture existed in the films with (100) preferred orientation. Polycrystalline diffraction rings were recorded for the film where preferred orientation was not obvious. The AIN film deposited at 2 mtorr exhibited improved grain orientation along the c-axis. A further decrease in sputtering pressure to 1.4 mtorr produced an AIN film with two-domain structure instead of a perfect single crystal. (C) 2002 Elsevier Science B.V. All rights reserved.