Direct Growth of Bi<sub>2</sub>SeO<sub>5</sub> Thin Films for High-k Dielectrics via Atomic Layer Deposition
Hyeonbin Park, Jae Hun Hwang, Seung Hoon Oh, Jin Joo Ryu, Kanghyeok Jeon, Minsoo Kang, Hyun‐Jun Chai, Ayoung Ham, Gun Hwan Kim, Kibum Kang, Taeyong Eom
Abstract
This study describes a modified atomic layer deposition (ALD) process for fabricating BiO x Se y thin films, targeting their application as high-k dielectrics in semiconductor devices, especially for two-dimensional semiconductors. Using an intermediate-enhanced ALD technique for Bi 2 Se 3 and a plasma-enhanced ALD process for Bi 2 O 3, a method for the sequential deposition of Bi 2 SeO 5 ternary films has been established. The thin film has been deposited on SiO 2 and TiN substrates, exhibiting growth rates of 0.17 to 0.16 nm·cycle –1 without an incubation period, thanks to facile nucleation characteristics. The resulting film exhibited high flatness and reached 96% of its theoretical density, forming a uniform nanocrystalline structure. Electrical evaluations using metal–insulator–metal capacitors indicated the dielectric constant (∼17.6) and electrical breakdown strength (2.6 MV·cm –1 ), demonstrating their potential as a dielectric layer.