Chemical Vapor Deposition of Aluminum Oxide Thin Films

Chemical vapor deposition (CVD) is a process routinely used to produce thin films of materials via decomposition of volatile precursor molecules. Unfortunately, the equipment required for a conventional CVD experiment is not practical or affordable for many undergraduate chemistry laboratories, especially at smaller institutions. In an effort to expose undergraduate chemistry students to this valuable materials science technique, a convenient, inexpensive apparatus was constructed to deposit thin films of aluminum oxide on a silicon wafer substrate. The system features the controlled hydrolysis of the water-sensitive precursor liquid, dimethylaluminumisopropoxide, at 200 °C. The experiment described herein is customizable depending on the resources available and lends itself to an inquiry-based format. A discussion of overall student sentiment and pedagogical outcomes from this module is also included.