A comparison of tungsten films grown by CVD and hot-wire assisted ALD

Description

Plasma-enhanced atomic layer deposition has been proposed as a suitable technique to grow metals [1]. In this work, we develop hot-wire assisted ALD (HWALD) where plasma is replaced by a tungsten filament heated up to 1700-2000 oC. Molecular H2 can efficiently dissociate on a heated filament, generating atomic hydrogen (at-H) [2]. In the current approach we utilize HWALD of tungsten (W) by alternating pulses of WF6 and at-H. A 100-nm SiO2 thermally grown on Si wafer was used as a substrate to enable electrical characterization of W films. Due to slow nucleation of W on SiO2, a 2-5 nm thin seed layer of W was pre-formed prior to ALD by (i) depositing a 5 nm amorphous Si (a-Si) layer using Si2H6 and (ii) introducing WF6 to convert the a-Si into a W layer. The growth behaviour was monitored in real time by an in-situ spectroscopic ellipsometer (SE).

Period	28 Jun 2015 → 1 Jul 2015
Event title	15th International Conference on Atomic Layer Deposition 2015
Event type	Conference
Conference number	15
Location	Portland, United States, OregonShow on map
Degree of Recognition	International