In:
Chinese Physics B, IOP Publishing, Vol. 31, No. 7 ( 2022-07-01), p. 077701-
Abstract:
Since defects such as traps and oxygen vacancies exist in dielectrics, it is difficult to fabricate a high-performance MoS 2 field-effect transistor (FET) using atomic layer deposition (ALD) Al 2 O 3 as the gate dielectric layer. In this paper, NH 3 in situ doping, a process treatment approach during ALD growth of Al 2 O 3 , is used to decrease these defects for better device characteristics. MoS 2 FET has been well fabricated with this technique and the effect of different NH 3 in situ doping sequences in the growth cycle has been investigated in detail. Compared with counterparts, those devices with NH 3 in situ doping demonstrate obvious performance enhancements: I on / I off is improved by one order of magnitude, from 1.33 × 10 5 to 3.56 × 10 6 , the threshold voltage shifts from –0.74 V to –0.12 V and a small subthreshold swing of 105 mV/dec is achieved. The improved MoS 2 FET performance is attributed to nitrogen doping by the introduction of NH 3 during the Al 2 O 3 ALD growth process, which leads to a reduction in the surface roughness of the dielectric layer and the repair of oxygen vacancies in the Al 2 O 3 layer. Furthermore, the MoS 2 FET processed by in situ NH 3 doping after the Al and O precursor filling cycles demonstrates the best performance; this may be because the final NH 3 doping after film growth restores more oxygen vacancies to screen more charge scattering in the MoS 2 channel. The reported method provides a promising way to reduce charge scattering in carrier transport for high-performance MoS 2 devices.
Type of Medium:
Online Resource
ISSN:
1674-1056
DOI:
10.1088/1674-1056/ac3bab
Language:
Unknown
Publisher:
IOP Publishing
Publication Date:
2022
detail.hit.zdb_id:
2412147-2
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