Optimization of the dry development for the DESIRE process

Abstract

In surface imaging, dry developed resist systems, based on gas phase silylation, resist profiles are mainly determined by the silicon distribution between the exposed and the unexposed areas in the upper part of the resist, and by the dry etching process that transfers this silicon image into the rest of the resist layer1 . Contrast enhancement, resulting in steeper roflles and less residues, is obtained by a two-step dry development process23. In a short first step, a small amount of a fluorinated gas is added to remove the upper thin layer of resist. This results In an elimination of residual silicon in the non-exposed areas and also in steeper silicon-profiles in the exposed regions, and thus in steeper resist profiles after dry development. Similar process improvements can be obtained using a two-step dry development process using pure oxygen. The selectivity is then controlled by increasing or decreasing physical sputtering.Instead of using fluorine containing gases for non-selectivity, the silicon, incorporated Into the non-exposed areas, is sputtered away physically In a first step by using elevated power and decreased flow rate conditions. With this in mind and with the help of a statistically designed experiment, The optimum process conditions for this pure oxygen, two-step development process were determined. The results are compared to those obtained using a single step development and to the two-step C2F6 process.

Plasma developable photoresist systems based on chemical amplification.

“…Therefore, the specific RIE parameters (RF power, pressure, flow) will strongly influence the quality of the final image (27). In this study, standard RIE process parameters were used to allow a direct comparison of the chemistry of the two polymeric systems.…”

<title>Effect of silylation condition on the silylated image in the DESIRE process</title>

“…For instance, the limitations of resolution in the DESIRE process [5], the methods of optimizing DESIRE process [6], mechanism of the DESIRE process [7,8], applications of mass production of ULSI[9, 1O,11], and only a few papers report the silylation kinetics [12,13]. For instance, the limitations of resolution in the DESIRE process [5], the methods of optimizing DESIRE process [6], mechanism of the DESIRE process [7,8], applications of mass production of ULSI[9, 1O,11], and only a few papers report the silylation kinetics [12,13].…”