Atomic Layer Deposition (ALD)
ALD is an important technique to deposit very thin films of a variety of materials. This CVD technique utilizes self-limiting surface chemistry along with the appropriate source gases to generate mono-layer films. The process sequences are computer controlled to enable repeated steps and the fabrication of thicker layers. One example is the use of trimethylaluminum (TMA) plus water vapor (H2O) to grow Al2O3 dielectrics. Extensive ALD development has been done in recent years by the semiconductor industry to develop thin high-K gate dielectric layers. Surface cleans and treatments are an important part of ALD film depositions. A wide array of materials have been developed for ALD applications; see the following references for more information.
- M. George, “Atomic Layer Deposition: An Overview”, Chem. Rev. (2010),110, p111-131. Note: contains 226 References!!