Measurement Of Deep Trenches To Study The RIE Lag Effect

The Zeta-20 optical profiler provides a quick, non-destructive method for measuring the profile and depth of high aspect ratio trenches to characterize the lag effect of reactive ion etching (RIE).


The demand for accurate characterization of high aspect ratio geometries such as narrow gaps, deep trenches or deep holes arises in many technologies and industries. A variety of metrology techniques have been utilized to accommodate these needs. Among the candidates for this type of metrology, 3D optical profiling characterization is becoming more and more prevalent in process control. Due to its non-destructive measurement method and excellent data accuracy, optical profiling is especially advantageous for delicate samples.

In this application note, deep trenches of varying width were etched into silicon using reactive ion etching (RIE). RIE processes are widely used in industry, but the development of these processes can be highly complex. Critical dimensions, aspect ratio and position all impact the etch rate, which is core to process development. An example of how the RIE etch depth can vary as a function of feature dimension is illustrated in Figure 1. This phenomenon is called RIE lag or ARDE (aspect ratio dependent etching), and it occurs frequently in the microfabrication process.

Click here to read more.

Leave a Reply

(Note: This name will be displayed publicly)