Sensitive negative resist for 405 nm laser direct exposure

Negative resist AR-N 4400-10 can be structured with laser direct exposure at an exposure wavelength of 405 nm. Different arrays are shown in the figure. The column diameter varies from 5 µm to 50 µm; the exposure dose was in a range between 7 mJ/cm² and 200 mJ/cm². In this test series, the film thickness was about 11 µm.

Test areas with different column diameters

40 µm-columns at a dose of 7 mJ/cm²

The sensitivity of the resist is exceptionally good. A dose of only 7 mJ/cm² is sufficient to realise a complete layer build-up. Other negative resists are exclusively designed for i-line (365 nm) exposure. Negative resist AR-N 4400-10 thus is in addition a good choice for various applications with 405 nm lasers. Even during g-line exposure (436 nm), the resist is still sufficiently sensitive. Especially notable is e.g. the structuring of irregularly shaped substrates which are coated by dip coating with the special resist AR-N 4340-10 S6 (a modification of AR-N 4400-10). In this case, exposure is not performed through masks, but using a laser.