I would like to fabricate micro needles in the dimension of 2 micro meter width and 20 micro meter length, Can any one help me how to prepare MASK layout and mask preparation.
Some people simply use CAD packages such as AutoCAD and then export as .GDS or .CIF or convert the files (i.e. from .DXF), but I have personally found this can lead to issues when importing to the DLW.
On the LayoutEditor webpage, there is an interesting page with a description of many GDS tools (not only to get a layout, but also to draw 3D devices thanks to the masks' datas, like PovRay). Many of them are free.
http://www.layouteditor.net/links/
Just to mention that GDS II is a standard of micro-electronics (used in Cadence for instance), even for e-Beam lithography. So I suggest using tools that natively use this format (and avoid conversion issues and fees to convert your datas).
In case of a plastic mask (depending on the resolution you need), you can use another formats but first check the wanted format to print them and the resolution of the printer. For instance, I have used PNG files, generated by hand, or by a script (PHP and Matlab), PDF files (thanks to Matlab+LaTex to draw periodic patterns)... for maks where a resolution of 10 µm was enought (6400 DPI printer)
You need a layout editor to draw your mask in a technology with a specific feature size to reach the required dimensions. This helps you to generate a gds2, or even oasis format file for mask fabrication.