Effect of Surface Orientation and Off-Angle on Surface Roughness and Electrical Properties of p-Type Impurity Implanted 4H-SiC Substrate after High Temperature Annealing

2006 ◽  
pp. 835-838
Author(s):  
Akimasa Kinoshita ◽  
Makoto Katou ◽  
Miwa Kawasaki ◽  
Kazutoshi Kojima ◽  
Kenji Fukuda ◽  
...  
Keyword(s):  
Surface Roughness ◽  
High Temperature ◽  
Electrical Properties ◽  
Surface Orientation ◽  
High Temperature Annealing ◽  
P Type ◽  
Effect Of Surface

Effect of Surface Orientation and Off-Angle on Surface Roughness and Electrical Properties of p-Type Impurity Implanted 4H-SiC Substrate after High Temperature Annealing

2006 ◽  
Vol 527-529 ◽  
pp. 835-838 ◽  
Author(s):  
Akimasa Kinoshita ◽  
Makoto Katou ◽  
Miwa Kawasaki ◽  
Kazutoshi Kojima ◽  
Kenji Fukuda ◽  
...  
Keyword(s):  
Surface Roughness ◽  
High Temperature ◽  
Annealing Temperature ◽  
Surface Orientation ◽  
Free Carrier ◽  
Root Mean Square Roughness ◽  
Mean Square ◽  
High Temperature Annealing ◽  
P Type ◽  
Effect Of Surface

We investigate the effect of surface orientation and off-angle for Al-implanted 4H-SiC samples after high temperature annealing. The samples are obtained from a 4H-SiC (0001) substrate 8° off-angled (Si-face 8°off), and (000-1) substrates 8° (C-face 8°off), 4° (C-face 4°off) and less than 1° off-angled (C-face ~1°off). An n-type epitaxial layer is deposited on all substrates. Multiple implantations of Al+ (30~200keV) are carried out at 600°C. The total dose is 8.6 × 1015 cm-2. The Al-implanted samples are annealed in Ar ambient at 1580°C, 1700°C and 1800°C for 30s using the hybrid super rapid thermal annealing (HS-RTA) equipment. In this study, sheet resistance (Rs), free carrier concentration (Ns), Hall mobility (μ) and root-mean square roughness (Rrms) are used to evaluate the Al-implanted samples after high temperature annealing. Rs for all Al-implanted samples after annealing at 1800°C for 30s is around 18k/. Rrms for the Al-implanted C-face samples after annealing at 1800°C increases with increasing off-angle. Rrms for the Al-implanted Si-face 8°off sample after annealing increases with annealing temperature. Rrms for the C-face ~1°off Al-implanted sample after annealing at 1800°C is lower than that for the Si-face 8°off Al-implanted sample after annealing at 1700°C, moreover Rs for the C-face ~1°off sample after annealing at 1800°C is about 10% of that for the Si-face 8°off Al-implanted sample after annealing at 1700°C. It is shown that the C-face ~1°off sample is useful to fabricate a p+ region with low Rs and low Rrms. If C-face 4H-SiC is used to fabricate devices, devices made on C-face 4H-SiC with low off angle are expected to decrease any problems caused by increase of surface roughness after high temperature annealing (~1800°C).

Study of the electrical properties of  Cz p-type solar-grade silicon wafers against the high-temperature processes

2021 ◽  
Vol 127 (6) ◽  
Author(s):  
Mohamed Maoudj ◽  
Djoudi Bouhafs ◽  
Nacer Eddine Bourouba ◽  
Abdelhak Hamida-Ferhat ◽  
Abdelkader El Amrani
Keyword(s):  
High Temperature ◽  
Electrical Properties ◽  
Silicon Wafers ◽  
Solar Grade Silicon ◽  
High Temperature Processes ◽  
Grade Silicon ◽  
P Type

Impact of CF4 Plasma Treatment on the Surface Roughness of Ion Implanted SiC Induced by High Temperature Annealing

2010 ◽  
Vol 645-648 ◽  
pp. 783-786
Author(s):  
Tatsunori Sugimoto ◽  
Masataka Satoh ◽  
Tohru Nakamura ◽  
K. Mashimo ◽  
Hiroshi Doi ◽  
...  
Keyword(s):  
Surface Roughness ◽  
High Temperature ◽  
Energy Range ◽  
Plasma Treatment ◽  
Surface Roughening ◽  
High Temperature Annealing ◽  
Small Surface ◽  
Step Structure ◽  
The Impact ◽  
Ion Implanted

The impact of CF4 plasma treatment on the surface roughening of SiC has been investigated for N ion implanted SiC(0001) which is implanted with the energy range from 15 to 120 keV at a dose of 9.2 x 1014/cm2. The N ion implanted sample, which is processed by CF4 plasma, shows small surface roughness of 1.6 nm after annealing at 1700 oC for 10 min, while the sample without CF4 plasma treatment shows the large surface roughness (6.6nm) and micro step structure. XPS measurements reveals that CF4 plasma treatment is effective to dissolved the residual oxide on the surface of SiC which is not removed by BHF acid of SiO2 layer on SiC. It is strongly suggested that the formation of micro step structure with the increase of the surface roughness is promoted by the residual oxide such as SiCOx, on SiC.

Suppression of SiC surface roughening during high-temperature annealing by atmospheric control using purified Ar gas

2010 ◽  
Vol 25 (4) ◽  
pp. 708-710 ◽  
Author(s):  
Atsushi Ogura ◽  
Daisuke Kosemura ◽  
Shingo Kinoshita
Keyword(s):  
Surface Roughness ◽  
High Temperature ◽  
Surface Roughening ◽  
Annealing Atmosphere ◽  
High Temperature Annealing ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After ◽  
Furnace Tube ◽  
Ar Gas

4H-silicon carbide (SiC) wafers were annealed at 1300 and 1600 °C for 30 min and 60 min in a conventional and purified Ar atmosphere. The surface roughness before and after annealing was evaluated by atomic force microscopy. The surface roughness before annealing was approximately 2.37 nm in root mean square. The roughness, after annealing for 30 min at 1300 and 1600 °C in a conventional Ar furnace, was increased to 4.53 and 14.9 nm, respectively. The roughness, after annealing for 60 min, was 5.01 and 19.1 nm, respectively. In this study, the G3 grade Ar gas (99.999%) was supplied in the conventional furnace tube. When the Ar gas was purified to an impurity concentration of less than 1 ppb, and it was supplied in the leak-tight furnace tube, the roughness after 30-min annealing improved 4.27 and 6.93 nm at 1300 and 1600 °C, respectively. The roughness after 60-min annealing was also reduced to 3.54 and 9.28 nm, respectively. We assume that a significant reduction of H2O concentration in the annealing atmosphere might play an important role in suppressing surface roughening of SiC during high-temperature annealing.

Correlation Study of Morphology, Electrical Activation and Contact formation of Ion Implanted 4H-SiC

2009 ◽  
Vol 156-158 ◽  
pp. 493-498
Author(s):  
Ming Hung Weng ◽  
Fabrizio Roccaforte ◽  
Filippo Giannazzo ◽  
Salvatore di Franco ◽  
Corrado Bongiorno ◽  
...  
Keyword(s):  
High Temperature ◽  
Surface Morphology ◽  
Electrical Activation ◽  
Structural Defects ◽  
High Resistivity ◽  
Al Alloy ◽  
High Temperature Annealing ◽  
Capping Layer ◽  
P Type ◽  
Ion Implanted

This paper reports a detailed study of the electrical activation and the surface morphology of 4H-SiC implanted with different doping ions (P for n-type doping and Al for p-type doping) and annealed at high temperature (1650–1700 °C) under different surface conditions (with or without a graphite capping layer). The combined use of atomic force microscopy (AFM), transmission electron microscopy (TEM), and scanning capacitance microscopy (SCM) allowed to clarify the crucial role played by the implant damage both in evolution of 4H-SiC surface roughness and in the electrical activation of dopants after annealing. The high density of broken bonds by the implant makes surface atoms highly mobile and a peculiar step bunching on the surface is formed during high temperature annealing. This roughness can be minimized by using a capping layer. Furthermore, residual lattice defects or precipitates were found in high dose implanted layers even after high temperature annealing. Those defects adversely affect the electrical activation, especially in the case of Al implantation. Finally, the electrical properties of Ni and Ti/Al alloy contacts on n-type and p-type implanted regions of 4H-SiC were studied. Ohmic behavior was observed for contacts on the P implanted area, whilst high resistivity was obtained in the Al implanted layer. Results showed a correlation of the electrical behavior of contacts with surface morphology, electrical activation and structural defects in ion-implanted, particularly, Al doped layer of 4H-SiC.

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