Area-Selective Atomic Layer Deposition of ZnO on Si\SiO2 Modified with Tris(dimethylamino)methylsilane
Author(s): Behnam Moeini1, Tahereh G. Avval1, Hidde H. Brongersma2, Stanislav Průša3,4, Pavel Bábík3,4, Elena Vaníčková3,4, Brian R. Strohmeier5, David S. Bell6, Dennis Eggett7, Steven M. George8, Matthew R. Linford1
1. Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602, USA, 2. Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands, 3.Institute of Physical Engineering, Brno University of Technology, Technická 2, 616 69 Brno, Czech Republic, 4. CEITEC BUT, Brno University of Technology, Purkyňova 123, 612 00 Brno, Czech Republic, 5. Materials Group-NA, Avery Dennison Corporation, 8080 Norton Parkway, Mentor, OH 44060, USA, 6. Restek Corporation, 110 Benner Circle, Bellefonte, PA 16823, USA, 7. Department of Statistics, Brigham Young University, Provo, UT 84602, USA, 8. Department of Chemistry, University of Colorado, 215 UCB, Boulder, CO 80309, USA
Published By: materials
Issue: 13, Volume 16
Year of Publication: 2023
Link: https://doi.org/10.3390/ma16134688
Abstract: Delayed atomic layer deposition (ALD) of ZnO, i.e., area selective (AS)-ALD, was successfully achieved on silicon wafers (Si\SiO2) terminated with tris(dimethylamino)methylsilane (TDMAMS). This resist molecule was deposited in a home-built, near-atmospheric pressure, flow-through, gas-phase reactor. TDMAMS had previously been shown to react with Si\SiO2 in a single cycle/reaction and to drastically reduce the number of silanols that remain at the surface. ZnO was deposited in a commercial ALD system using dimethylzinc (DMZ) as the zinc precursor and H2O as the coreactant. Deposition of TDMAMS was confirmed by spectroscopic ellipsometry (SE), X-ray photoelectron spectroscopy (XPS), and wetting. ALD of ZnO, including its selectivity on TDMAMS-terminated Si\SiO2 (Si\SiO2\TDMAMS), was confirmed by in situ multi-wavelength ellipsometry, ex situ SE, XPS, and/or high-sensitivity/low-energy ion scattering (HS-LEIS). The thermal stability of the TDMAMS resist layer, which is an important parameter for AS-ALD, was investigated by heating Si\SiO2\TDMAMS in air and nitrogen at 330 °C. ALD of ZnO takes place more readily on Si\SiO2\TDMAMS heated in the air than in N2, suggesting greater damage to the surface heated in the air. To better understand the in situ ALD of ZnO on Si\SiO2\TDMAMS and modified (thermally stressed) forms of it, the ellipsometry results were plotted as the normalized growth per cycle. Even one short pulse of TDMAMS effectively passivates Si\SiO2. TDMAMS can be a useful, small-molecule inhibitor of ALD of ZnO on Si\SiO2 surfaces.