Dear All,

Recently, I use AFM to fabricate micro-nano structure, along with other
methods such as wet etching, sputter and photolithography.
The first step is to fabricate nano-grating by AFM. I have used many
photoresists such as SU-8 and AZ1800. I find that SU-8 is too
sticky to form a groove. AZ1800 is better than SU-8, however, depth-to-width
ratio is too small(1:10). The height of the groove is about
100nm, the groove bottom is about 300 nm, and the dap is nearly 750nm.

Tip Radius (max.) is 20nm. What is the main reason that the dap comes to
750nm?

I still can not find a suitable photoresist for AFM scratching.
If you have advice, please tell me in details.
Your help will be highly appreciated.

Thank you!

Liuchang