**6. Conclusion**

I have described an electron beam (EB) lithography using a raster drawing for fabrication of nanometer sized dot or pit arrays, theoretically and experimentally. I considered the possibility to form the nanometer-sized pitch fine dot arrays by the energy deposition distribution (EDD) calculated by the home-made Monte Carlo simulation. The experimental research is done by dependences of 2 resist materials (ZEP520 and calixarene) and thickness on the drawn dot size and pitch in EB drawing. I have used a conventional EB drawing system based on high resolution-scanning electron microscope (HR-SEM). As results using both positive and negative resists with thin thickness. I can demonstrate the possibility to form nanometer-sized dot and fine pitched dot arrays as follows.

1. The simulation shows that the EDD profile seems to be cone shape, which is very suitable for formation of nanometer-sized dots using negative resist, while it is not suitable in a case of using positive resist.


Furthermore, we try to form 15 nm x 15 nm pitched resist dot arrays using HSQ negative EB resist. We have gotten a prospect to form them by improving a developer for the resist. There are some papers to improve them using HSQ negative resist. X. Yang et al. have reported 12 nm x 12 nm or 15 nm x 15 nm pitch fine resist dot arrays using 100 keV EB drawing with hot developer of TMAH at 40 oC [6]. In addition, J. K. Yang et al. have reported 12 nm or 14 nm pitch resist line and space pattern EB-drawn using 100 keV EB drawing with salty development [27].

On the other hand, it is crucial to improve the resolution of SEM to check whether the EBdrawn pattern is complete or not. We should get high resolution observation method for very fine pitch dot arrays with a pitch of less than 15 nm x 15 nm.
