AIN thin films were deposited by ECR PECVD method using TMA and $N_2$ gas. Since highly c-axis oriented AIN films have good piezoelectric properties applicable to the SAW device, the crystallinity and c-axis orientation of the films were investigated by XRD rocking curves. The changes in film quality with variable deposition temperature and microwave power were analyzed by AES, FTIR, SEM and XRD.
The AIN thin films were deposited on Si(111) substrates. AIN thin films of highly c-axis oriented and with low impurity level were obtained at a low temperature of 500℃ by ECR PECVD method. When $H_2$ gas was used as a TMA carrying gas the impurity in the films came to disappear and the native oxide at the interface between AIN and Si substrate was reduced greatly. The crystallinity and c-axis orientation of the film were improved as the deposition temperature and microwave power increased. And the decomposition and activation of TMA in ECR plasma affected the impurity level and crystallinity of the AIN thin film a lot.
