In:
Applied Physics Letters, AIP Publishing, Vol. 111, No. 8 ( 2017-08-21)
Abstract:
In this paper, the effect of atomic layer deposited ZrO2 gate dielectrics, deposited at low temperature (100 °C), on the characteristics of recessed-gate High Electron Mobility Transistors (HEMTs) on Al0.25Ga0.75N/GaN/Si is investigated and compared with the characteristics of those with ZrO2 films deposited at typical atomic layer deposited (ALD) process temperatures (250 °C). Negligible hysteresis (ΔVth & lt; 20 mV), low gate leakage current (Ig@2 V = 6.6 × 10−6 A/cm2), high breakdown voltage ( & gt;4 V), and low interfacial state density (Dit = 3.69 × 1011 eV−1 cm−2) were observed on recessed gate HEMTs with ∼5 nm ALD-ZrO2 films grown at 100 °C. The excellent properties of recessed gate HEMTs are due to the absence of an interfacial layer and an amorphous phase of the film. An interfacial layer between 250 °C-ZrO2 and GaN is observed via high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. However, 100 °C-ZrO2 and GaN shows no significant interfacial layer formation. Moreover, while 100 °C-ZrO2 films maintain an amorphous phase on either substrate (GaN and Si), 250 °C-ZrO2 films exhibit a polycrystalline-phase when deposited on GaN and an amorphous phase when deposited on Si. Contrary to popular belief, the low-temperature ALD process for ZrO2 results in excellent HEMT performance.
Type of Medium:
Online Resource
ISSN:
0003-6951
,
1077-3118
Language:
English
Publisher:
AIP Publishing
Publication Date:
2017
detail.hit.zdb_id:
211245-0
detail.hit.zdb_id:
1469436-0
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