Electrical Characteristics of SiO₂ Deposited by Atomic Layer Deposition on 4H–SiC After Nitrous Oxide Anneal

Abstract

Properties of SiO 2 gate dielectric deposited by atomic layer deposition (ALD) on Si-face of 4H silicon carbide (SiC) were systematically studied. The interface state and effective fixed charge densities of ALD SiO 2 on n-type 4H-SiC with various post deposition anneal (PDA) conditions were evaluated. It has been found that nitrous oxide (N 2 O) PDA not only reduces the effective fixed charge density, which includes the fixed oxide charge and charged interface states, at SiC/SiO 2 interface but also decreases the gate leakage current. Negative effective fixed charge is observed at SiC/ALD SiO 2 interface after N 2 O PDA. ALD SiO 2 -based lateral n-channel MOSFETs show high threshold voltage with the promising fieldeffect mobility and the peak field-effect mobility increases with N 2 O PDA temperature.

High-mobility SiC MOSFET with low density of interface traps using high pressure microwave plasma oxidation*

“…As shown in Fig. 5(d), to our knowledge, this work is the record low published D it in SiO 2 /SiC system, [9,14,[24][25][26][27][28][29][30][31] confirming the effectiveness of high-pressure oxidation in forming high quality SiO 2 /SiC stack. And it is found that the breakdown field for the 1000-W sample could reach 10 MV/cm, as shown in Fig.…”

Review of Silicon Carbide Processing for Power MOSFET

“…To reduce the interface trap density for further improving the device performances, a thin insulator with a high dielectric constant and a large bandgap was deposited by atomic layer deposition (ALD) technology [105][106][107][108][109]. Several ALD materials such as Al 2 O 3 , AlN, and ZrO 2 have also exhibited the ability to improve the properties of power electronic components significantly [110][111][112].…”

Charge Sheet Super Junction in 4H-Silicon Carbide: Practicability, Modeling and Design

“…The controllability of the charge at the SiO2 / 4H-SiC interface does not affect the CSSJ operation. This is because, decades of research has reduced this charge from 5 × 10 12 cm -2 [26] to 3 × 10 11 cm -2 [27], i.e. to < 10 % of NI of (9).…”