An alternative Zr source to tetrakis(ethylmethylamino)zirconium (TEMAZr) was evaluated in this study to develop more thermally robust 300mm ZrO2 ALD process. It was observed that a transition from ALD to CVD takes place at approximately 340åC susceptor temperature. This temperature is significantly higher than that for the commonly used TEMAZr-based ALD process by approximately 40åC. Excellent step coverage of near 100% of ALD ZrO2 has been achieved in 40:1 aspect ratio structures using this new ZrO2 ALD process. ZrO2 ALD films of 5.5nm thickness demonstrated a low leakage current of 2x10-9A/cm2 at 1.2V.
Y. Senzaki, Okuyama, Y., Kim, G., Kim, H. Young, Barelli, C., Lindner, J., Karim, Z., and Dr. Sasangan Ramanathan, “Highly Conformal ALD of ZrO2 at Higher Process Temperatures than the Conventinal TEMAZr-Based Process”, ECS Transactions, vol. 25, pp. 201–209, 2009.