In Part 1 of our deposition rate and uniformity series, we discussed the key considerations for deposition tool performance. The second part of our series takes a look at the steps for deposition system design based on rate and uniformity.

What are the key parameters of interest to anyone selecting a tool for thin film deposition? They are, of course, the film properties themselves. Concerning the process of growing the film, the most fundamental are the deposition rate and film thickness uniformity. The rate is important to reach proper film thickness in single or multi-layers, and to achieve stoichiometry in co-deposited films. The rate also correlates to how economically viable the system will be via the throughput: how long it will take to create the layer needed to serve a particular purpose. The uniformity determines how much of the film area will hold to these metrics over the entire area of the substrate, to within a desired tolerance.

Thin film deposition systems are famously long-lived. With proper maintenance, instruments can last for decades! That said, with the ever-advancing march of technology, most systems eventually fall short of demands for higher throughput or improved yield. When that occurs, the deposition system will generally require a major overhaul in order to accommodate new modes of automation and advanced computer controls. When upgrades are not possible or feasible, it may be time to replace the entire system. The primary concern during such a change is maintaining consistency of performance between the old and new systems. It is imperative that films produced from the new deposition tool match that of the previous tool.