The Dry Development Process of Tmsdea-Treated Photoresist by Using Oxygen-Helium Plasma in Reactive Ion Etching Mode
- PDF / 964,015 Bytes
- 6 Pages / 420.48 x 639 pts Page_size
- 7 Downloads / 146 Views
THE DRY DEVELOPMENT PROCESS OF TMSDEA-TREATED PHOTORESIST BY USING OXYGEN-HELIUM PLASMA IN REACTIVE ION ETCHING MODE KWANG-HO KWON, SUN JIN YUN, BYUNG-SUN PARK, AND YOUNG-JIN JEON Electronics &Telecommunications Research Institute, Daedog Danji P.O. Box 8, Daejeon, 305-606, Korea ABSTRACT Silylation and dry development are the key processes of DESIRE, one of the surface imaging techniques in submicron lithography. The present work was carried out to achieve the improvement of develoment rate and anisotropic resist profile, and to characterize the silylated and dry developed resist. The dependence of silylation on the exposure dose and the presilylation baking temperature was investigated by using Rutherford backscattering spectrometry. The higher dose UV-irradiation results the thicker silylated layer in the dyed resist. The dry development of photoresisl patterns was processed newly by using the plasma of 0 2 /He RIE plasma. It is particularly emphasized to obtain to optimize the RIE process, so that some improvements, i.e., vertical resist profiles with the high anisotropy, good selectivity, and the development rate of 0.4 lim/min were achieved. X-ray photoelectron spectroscopic study indicated that Si in the silylaled and dry developed resist was present with the chemical binding states of Si0 2 on surface. and SiO. SiC and very small amount of Si0 2 in near-Surface region (at about 5 nm depth). INTRODUCTION In recent years, various techniques to overcome many limitations have been studied extensively in optical submicron lithography. The important problems to be solved in the submicron lithography techniques are the shallower focus budgets of high NA lenses, the sloped profiles resulting from absorption and the resist image degradation due to the topography and reflectivity of the substrate. An approach to solve most of the problems is the so-called multilayer resist technique. The best results have been obtained using trilayer resist systems[I]. However, they unfortunately have the many problems which are complex and more susceptible to pinhole problem resulting in defects of underlayer. These considerations make trilayer techniques unattractive to large scale production lines. An alternative is the diffusion-enhanced silylating resist(DESIRE) process[2,3], making use of surface imaging. This is a monolayer/ dry developed resist system that increases resolution and process latitude without increasing complexity. The dry development in the DESIRE technology is a key process step and basically requires high anisotropy and good selectivity between the thin masking layer and the resist. The dry development is generally carried out in magnetically-enhanced reactive ion etching (MIE)[4,5], because the etch rate and the resolution of the MIE mode is superior to reactive ion etching (RIE)[6]. However, RIE must be an attractive option to the dry development since MIE technique has some problems which are difficult and expensive to maintain the uniform magnetic field. Furthermore RIE technique has been more widcespreadl
Data Loading...
