TY - JOUR
T1 - Area-Selective Atomic Layer Deposition of TiN Using Aromatic Inhibitor Molecules for Metal/Dielectric Selectivity
AU - Merkx, Marc J.M.
AU - Vlaanderen, Sander
AU - Faraz, Tahsin
AU - Verheijen, Marcel A.
AU - Kessels, Wilhelmus M.M.
AU - MacKus, Adriaan J.M.
PY - 2020/9/22
Y1 - 2020/9/22
N2 - Despite the rapid increase in the number of newly developed processes, area-selective atomic layer deposition (ALD) of nitrides is largely unexplored. ALD of nitrides at low temperature is typically achieved by employing a plasma as the coreactant, which is not compatible with most approaches to area-selective ALD. In this work, a plasma-assisted ALD process for area-selective deposition of TiN was developed, which involves dosing of inhibitor molecules at the start of every ALD cycle. Aromatic molecules were identified as suitable inhibitor molecules for metal/dielectric selectivity because of their strong and selective adsorption on transition metal surfaces. A four-step (i.e., ABCD-type) ALD cycle was developed, which comprises aniline inhibitor (step A) and tetrakis(dimethylamino)titanium precursor (step B) dosing steps, followed by an Ar-H2 plasma exposure (step C), during which a substrate bias is applied in the second half of the plasma exposure (step D). This process was demonstrated to allow for ∼6 nm of selective TiN deposition on SiO2 and Al2O3 areas of a nanoscale pattern with Co and Ru non-growth areas. The TiN deposited using this ABCD-type process is of high quality in terms of resistivity (230 ± 30 μω cm) and impurity levels. This developed strategy for area-selective ALD of TiN can likely be extended to area-selective ALD of other nitrides.
AB - Despite the rapid increase in the number of newly developed processes, area-selective atomic layer deposition (ALD) of nitrides is largely unexplored. ALD of nitrides at low temperature is typically achieved by employing a plasma as the coreactant, which is not compatible with most approaches to area-selective ALD. In this work, a plasma-assisted ALD process for area-selective deposition of TiN was developed, which involves dosing of inhibitor molecules at the start of every ALD cycle. Aromatic molecules were identified as suitable inhibitor molecules for metal/dielectric selectivity because of their strong and selective adsorption on transition metal surfaces. A four-step (i.e., ABCD-type) ALD cycle was developed, which comprises aniline inhibitor (step A) and tetrakis(dimethylamino)titanium precursor (step B) dosing steps, followed by an Ar-H2 plasma exposure (step C), during which a substrate bias is applied in the second half of the plasma exposure (step D). This process was demonstrated to allow for ∼6 nm of selective TiN deposition on SiO2 and Al2O3 areas of a nanoscale pattern with Co and Ru non-growth areas. The TiN deposited using this ABCD-type process is of high quality in terms of resistivity (230 ± 30 μω cm) and impurity levels. This developed strategy for area-selective ALD of TiN can likely be extended to area-selective ALD of other nitrides.
UR - http://www.scopus.com/inward/record.url?scp=85093099170&partnerID=8YFLogxK
U2 - 10.1021/acs.chemmater.0c02370
DO - 10.1021/acs.chemmater.0c02370
M3 - Article
AN - SCOPUS:85093099170
VL - 32
SP - 7788
EP - 7795
JO - Chemistry of Materials
JF - Chemistry of Materials
SN - 0897-4756
IS - 18
ER -