Abstract
Due to the chemically inert surface of MoS2, uniform deposition of ultrathin high-κ dielectric using atomic layer deposition (ALD) is difficult. However, this is crucial for the fabrication of field-effect transistors (FETs). In this work, the atomic layer deposition growth of sub-5 nm La2O3/Al2O3 nanolaminates on MoS2 using different oxidants (H2O and O3) was investigated. To improve the deposition, the effects of ultraviolet ozone treatment on MoS2 surface are also evaluated. It is found that the physical properties and electrical characteristics of La2O3/Al2O3 nanolaminates change greatly for different oxidants and treatment processes. These changes are found to be associated with the residual of metal carbide caused by the insufficient interface reactions. Ultraviolet ozone pretreatment can substantially improve the initial growth of sub-5 nm H2O-based or O3-based La2O3/Al2O3 nanolaminates, resulting in a reduction of residual metal carbide. All results indicate that O3-based La2O3/Al2O3 nanolaminates on MoS2 with ultraviolet ozone treatment yielded good electrical performance with low leakage current and no leakage dot, revealing a straightforward approach for realizing sub-5 nm uniform La2O3/Al2O3 nanolaminates on MoS2.
Highlights
Silicon complementary metal-oxide-semiconductor (CMOS) devices continuing shrink in size, and keeping the generation of heat low has becoming extremely challenging [1,2].One promising alternative approach is to use transition metal dichalcogenides (TMDs) due to their extraordinary electronic and mechanical properties [3,4]
La2 O3 /Al2 O3 nanolaminates on MoS2, which indicates that it is difficult to grow uniform ultrathin dielectric directly on MoS2
This may be explained by that, O3 has higher reactivity due to its strong oxidizing ability, it is easy to decompose to O2 and monatomic O during the atomic layer deposition (ALD) reactions, the monatomic O radical diffusion and desorption will significantly affect the growth of the film
Summary
Silicon complementary metal-oxide-semiconductor (CMOS) devices continuing shrink in size, and keeping the generation of heat low has becoming extremely challenging [1,2]. La2O3 has a high dielectric constant (~26), large cope with these challenges, the pretreatment of a MoS2 surface with oxygen band eV), andofthe drawbackseeding of moisture absorption can be greatly by plasmagap [13],(~5.8 introduction an additional layer [14], ultraviolet ozone (UV-O3 )improved [15], mixedplasma with atreatment less hygroscopic oxide. It has been nm studied as Al the Ocandidate water [16] have been demonstrated. Few layers MoS2 film was directly deposited by RF magnetron
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
