Interface trap passivation for SiO2∕(0001¯) C-terminated 4H-SiC

Abstract

Interface trap passivation at the SiO2∕carbon-terminated (0001¯) face of 4H-SiC utilizing nitridation and hydrogenation has been evaluated. The SiO2∕SiC interface, created by dry thermal oxidation on the C face, shows appreciably higher interface state density near the conduction band compared to the (0001) Si face. A postoxidation anneal in nitric oxide followed by a postmetallization anneal in hydrogen results in dramatic reduction of the trap density by over an order of magnitude near the conduction band. The electrical measurements have been correlated with the interfacial chemistry.

Defect levels of carbon-related defects at the SiC/SiO2interface from hybrid functionals

“…Recently, it was shown that a post oxidation anneal in nitric oxide followed by a post metallization anneal in hydrogen through a platinum gate known to catalyze atomic hydrogen formation resulted in a reduction of the trap density by over an order of magnitude near the conduction band. 9,10 It was suggested that this treatment could eliminate the threefold coordinated atoms responsible for the high interface trap density either by hydrogen passivation or by nitrogen replacement. 10,11 Recent density-functional calculations shed some light on both the atomic-scale oxidation mechanism of 4H-SiC and the nature of possible defects at the SiC/SiO 2 interface.…”

Interface State Density between Direct Nitridation Layer and SiC Estimated from Current Voltage Characteristics of MIS Schottky Diode

“…These process resulted in the interface state density of 10 12 eV −1 cm −2 , or less, at about 0.2 eV below conduction band edge [7]. The values shown in Fig.…”

Hydrogen Incorporation Dependence on the Thermal Growth Route in Dielectric/SiC Structures

“…After the annealing and the system has reached room temperature, the D 2 atmosphere was removed by pumping the system down to ∼10 −5 mbar. The use of hydrogen atmosphere enriched in the deuterium isotope ( 2 H = D) assumes that it mimics the behavior of the 1 H. Platinum (Pt) was chosen as the metal electrode due to its catalytic effect in dissociating H 2 molecules into atomic hydrogen, 10 which is more likely to be incorporated than molecular hydrogen.…”

“…4,8 The effect of the incorporation of N was related to both the removal and the passivation of residual C in the dielectric/SiC interface region. [9][10][11] The use of POA in H 2 also led to reduction in D it below the conduction band for n-type 4H-SiC (0001) MOS structures 12 and improve the channel mobility of 4H-SiC (0001) MOSFETs. 13 Moreover, combining POAs in NO and in H 2 using platinum (Pt) as the electrode metal caused a complementary reduction in D it 10,14 and enhanced field-effect mobility in 4H-SiC (0001) MOSFETs 15 compared with only NO or only H 2 annealings.…”

“…[9][10][11] The use of POA in H 2 also led to reduction in D it below the conduction band for n-type 4H-SiC (0001) MOS structures 12 and improve the channel mobility of 4H-SiC (0001) MOSFETs. 13 Moreover, combining POAs in NO and in H 2 using platinum (Pt) as the electrode metal caused a complementary reduction in D it 10,14 and enhanced field-effect mobility in 4H-SiC (0001) MOSFETs 15 compared with only NO or only H 2 annealings. The passivation effect of POA in H 2 has been investigated only in the case of thermal growth in O 2 with and without POA in NO, but the consequences of POA in H 2 in dielectric films directly grown in NO still remain unknown.…”