No abstract

This paper clarifies the reaction order of photoresist removal using atomic hydrogen by investigating the relationship between atomic hydrogen density (nH) and photoresist removal rate (vrmv). Atomic hydrogen was generated by decomposing hydrogen molecules with a tungsten hot-wire catalyst. In the reaction between atomic hydrogen and photoresist, we found that vrmv increases in direct proportion to nH and revealed that the reaction exhibited a first-order kinetics with respect to nH.

Instead of photoresist removal methods using chemicals, we investigated an environmentally friendly removal method using atomic hydrogen generated by decomposing hydrogen molecules by contact with a hot-wire tungsten catalyst. We set the distance between the catalyst and the photoresist substrate (D CS ) at 20, 60, 100 and 120 mm and evaluated the apparent activation energy (E AP ) for the reaction between photoresist and atomic hydrogen at each D CS . The E AP was determined from Arrhenius plots of the photoresist removal rate against the average substrate temperature. When D CS was 20 and 60 mm, E AP decreased with increasing catalyst temperature (WT ¼ 2040 { 2420 C) and was not constant. However, when D CS was 100 and 120 mm, E AP was nearly constant at 19 AE 1 kJ/mol without depending on WT . We might obtain the activation energy of about 19 kJ/mol in the reaction of photoresist with atomic hydrogen.

In this paper, we investigated the removal characteristic of positive-tone novolak photoresists into which B, P, and As ions were implanted with doses of 5×1012–5×1015atoms/cm2 at an acceleration energy of 70 keV using atomic hydrogen, and the hardening mechanisms for the photoresists. All of the ion-implanted photoresists with doses up to 5×1015atoms/cm2 were removed without regard for ion species. The removal rates of the photoresists decreased with increasing ion-implantation dose due to hardening of the photoresist surfaces with implantation. The thickness of the surface-hardened layer of the photoresists decreased in the order of B→P→As , and the removal rate increased with decreasing thickness. The energy supplied from the ions to the photoresist concentrated on the surface side in the order of B→P→As , and the impact of the heavier ion on the photoresist was greater than that of the lighter ion. We deduced that the photoresists exhibited carbonization and cross-linkage attributable to the decrease in OH, CH, and O 1s and the increase in C=C , C 1s, and π-conjugated systems.

Effects of excess oxygen introduced during sputter deposition on carrier mobility in as-deposited and postannealed indium-tin-oxide films