AVS 66th International Symposium & Exhibition
    Atomic Scale Processing Focus Topic Monday Sessions
       Session AP+2D+EM+PS+TF-MoM

Invited Paper AP+2D+EM+PS+TF-MoM5
Area-Selective Deposition of TiO2 using Isothermal Integrated Atomic Layer Deposition and Atomic Layer Etching in a Single Reaction Chamber

Monday, October 21, 2019, 9:40 am, Room A214

Session: Area Selective Deposition and Selective-Area Patterning
Presenter: Gregory Parsons, North Carolina State University
Authors: G.N. Parsons, North Carolina State University
S.K. Song, North Carolina State University
H. Saare, North Carolina State University
Correspondent: Click to Email
Several new approaches are emerging where chemical etching is being coupled with atomic layer deposition to achieve area-selective deposition of dielectrics and metals. During ALD, selectivity is generally lost when undesired nuclei form on the targeted non-growth surface. These undesired nuclei can sometimes be removed by periodic etching, improving the overall selectivity. However, it is not known to what extent these coupled deposition/etching sequences can proceed while maintaining good selectivity. As desirable deposition and etching reactions proceed, other changes in the process can occur to enhance unwanted nucleation and/or impede desired etching, thereby limiting the net selectivity. Recent experiments in our lab have used in-situ probes to explore coupled thermal ALD and ALE super-cycles, performed sequentially under isothermal conditions in a single reaction chamber, to achieve area selective deposition of TiO2 on SiO2 with hydrogen-terminated silicon (100) as the desired non-growth surface. We find that as ALD/ALE super-cycles proceed, small changes occur in the ALD and ALE reactions, particularly during the transition from ALD to ALE, or from ALE to ALD. Also, modeling studies allow us to quantitatively analyze the ASD results and compare our findings to other known approaches. These insights will be helpful to understand opportunities and challenges in advanced atomic scale reactions and process implementation.