Trilayer process resist images

Figure 2.16, Scanning electron micrograph of resist images generated in a trilayer process. This figure shows the vertical walls and the absence of line width variations where the pattern crosses topographic features. Reproduced from reference 3. Copyright 1984 American Chemical Society)...

A simplification of the trilayer process involves combining the oxygen etch resistance of the silicon dioxide layer and the imaging characteristics of the top imaging layer (Figure 13). This converts the trilayer scheme to a bilayer scheme and eliminates one coating step and one etch step. In this process... 

The concept for this selective image transfer process can be seen in Figure 12 for a trilayer resist scheme. In this scheme the device topograhy is first overcoated with a high temperature planarizing polymer, as discussed in the preceding section, such as a conventional novolac/NDS... 

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