We investigated the fabrication of convex diamond-like carbon (DLC) based
microgears in room-temperature curing nanoimprint lithography (RTC-NIL) using
the ladder-type hydrogen silsesquioxane (HSQ), as an application for the medical
micro electro mechanical system (MEMS). The HSQ which is an inorganic polymer of
sol-gel system turns into a gel when exposed to air and has the siloxane bond.
Therefore, the HSQ was used as RT-imprinting material, and also used as an oxide
mask material in electron cyclotron resonance (ECR) oxygen (O2) ion
shower etching. We fabricated the polydimethylsiloxane (PDMS) mold with concave
microgear patterns which has 40, 50 and 60 μm-tip diameter and 300
nm-depth. We carried out the RTC-NIL process using the PDMS mold under the
following optimum conditions of 0.10 MPa-imprinting pressure and 1.0
min-imprinting time. We found that the residual layer of imprinted HSQ microgear
patterns was removed with ECR trifluoromethane (CHF3) ion shower
under the following conditions of 300 eV-ion energy and 2.0 min-etching time,
and then microgears of the HSQ on the DLC film were etched with ECR
O2 ion shower under the following conditions of 400 eV-ion energy and
10 min-etching time. As a result, the convex DLC based microgears which have 40,
50 and 60 μm-tip diameter and 400 nm-height were fabricated with high
accuracy in the new fabrication process of RTC-NIL.