UV NIL process
 |
|
Nano photodetector on stamp
| In comparison with conventional thermal type NIL, UV-NIL utilizes UV light sensitive photo resist as imprint resist. After the stamp is imprinted into the resist, the nanofeatures in the resist can be cured and fixed by UV light illumination through the stamp. It has advantages in terms of no dimensional changes by thermal expansion, capability of rapid processes without heat cycle as heating and cooling, and capability of processes on large area with low pressure.
The imprint resolution is mainly dependent on nanofeature dimensions on the stamp. Therefore a precision stamp is one of key factors to achieve high quality NIL process for fabricating nanodevices. Usually a UV light transparent stamp is fabricated on quartz by combination of ebeam lithography and dry etching technique, an example of nanodevices on our currently used quartz stamp is shown in the figure on the right.
A typical UV-NIL process flow and a few imprinted nanodevices are illustrated as follows:
| (a) |
Hard mask layer, for instance, thin metal layer or SiO2 layer deposition and then UV curable resist coating |
| (b) |
Imprint into the resist |
| (c) |
Demount the stamp |
| (d) |
Dry etching for break through the remaining resist |
| (e) |
Form the nano features into hard mask layer by dry etching and then remove residual resist |
| (f) |
Transfer the nano patterns into substrate |
|
Imprinted nano resonator
|
|
Imprinted nano switcher
|
|
Imprinted nano structure for sensor application
|
|
|
 |
|
|