Effects of Rapid Thermal Processing on SiO2/GaAs Interfaces

1988 ◽  
Vol 126 ◽  
Author(s):  
Yutaka Tokuda ◽  
Masayuki Katayama ◽  
Nobuo Ando ◽  
Akio Kitagawa ◽  
Akira Usami ◽  
...  

ABSTRACTEffects of rapid thermal processing (RTP) on SiO2/GaAs interfaces have been investigated with Auger electron spectroscopy and X-ray photoelectron spectroscopy. SiO2 films of 100, 175, 200 and 1250 nm thickness have been deposited on liquid encapsulated Czochralski-grown (100) n-type GaAs wafers by the RF sputtering method. RTP has been performed at 800°C for 6 s. For comparison, conventional furnace processing (CFP) has also been performed at 800°C for 20 min for 200-nm-thick SiO2/GaAs. The Ga is observed on the outer SiO2 surface for RTP samples as well as CFP samples. This indicates that the outdiffusion of Ga occurs after only 6 s at 800°C even through 1250-nm-thick SiO2 films. The depth profile of Ga reveals the pile-up of Ga on the outer SiO2 surface for both RTP and CFP samples. The amount of Ga on the outer surface gradually increases in the thickness range 1250 to 175 nm. The As is also observed on the outer surface. The amount of Ga and As on the outer surface rapidly increases at 100 nm thickness. Electron traps in RTP samples have been studied with deep-level transient spectroscopy. Different electron traps are produced in GaAs by RTP between 100-nm- and 200-nm-thick SiO2/GaAs. It is thought that the production of different traps by RTP is related to the amount of Ga and As loss through SiO2 films from GaAs.

1989 ◽  
Vol 146 ◽  
Author(s):  
Masayuki Katayama ◽  
Yutaka Tokuda ◽  
Nobuo Ando ◽  
Akio Kitagawa ◽  
Akira Usami ◽  
...  

ABSTRACTEffects of rapid thermal processing (RTP) on SiO2/GaAs interfaces have been studied with X-ray photoelectron spectroscopy, capacitance-voltage measurements and deep-level transient spectroscopy. SiO2 films of 50, 200 and 1250 nim thickness have been deposited on GaAs. RTP has been performed at 760 and 910°C for 9 s. The rapid diffusion of Ga through the SiO2 film occurs, and the As loss and the formation of the As layer near the interface are observed. The decrease of the carrier concentration occurs in all RTP samples. Five electron traps EAI (Ec – 0.27 eV), EA2 (Ec – 0.32 eV), EA3 (Ec – 0.47 eV), EA4 (Ec – 0.58 eV) and EL2 (Ec – 0.78 eV) are produced by RTP. It is considered that the production of the trap EL2 is closely related to the Ga outdiffusion into the SiO2 film and the As indiffusion from the pile-up of elemental As near the interface. Effects of SiO2 film thickness on RTP-SiO2/GaAs are also reported.


1988 ◽  
Vol 126 ◽  
Author(s):  
H. Ueda ◽  
A. Kitagawa ◽  
Y. Tokuda ◽  
A. Usami ◽  
T. Wada ◽  
...  

ABSTRACTUsing deep level transient spectroscopy we have studied the variations of electron traps in molecular beam epitaxial (MBE) AlxGa1−xAs by rapid thermal processing (RTP) using halogen lamps. RTP was performed at 700, 800 and 900 °C for 6s under a SiO2 cap and a capless condition. It is found that during RTP the electron traps with the thermal activation energies of 0.89 and 0.99 eV are produced in Al0.lGa0.9As and Al0.3Ga0.7As, respectively. The thermal activation energies of these traps are close to the reported ones for the trap EL2 in AlxGaM1−xAs. Therefore, these traps are probably related to the trap EL2. In the RTP samples under a capless condition, the concentrations of the trap EL2 in AlxGa1−xAs (x=0.1, 0.3) decreases from the surface to the deeper position in MBE layers, while the depth profile of the trap EL2 in GaAs is flat. It is suggested that the origin of the trap EL2 formation in AlxGa1−xAs is different from one in GaAs.


1987 ◽  
Vol 92 ◽  
Author(s):  
Akio Kitagawa ◽  
Yutaka Tokuda ◽  
Akira Usami ◽  
Takao Wada ◽  
Hiroyuki kano

ABSTRACTRapid thermal processing (RTP) using halogen lamps for a Si-doped molecular beam epitaxial (MBE) n-GaAs layers was investigated by deep level transient spectroscopy. RTP was performed at 700°C, 800°C and 900°C for 6 s. Two electron traps NI ( Ec-0.5-0.7eV) and EL2 (Ec - 0.82 eV) are produced by RTP at 800 and 900°C.The peculiar spatial variations of the Nl and EL2 concentration across the MBE GaAs films are observed. The larger concentrations of the trap N1 and EL2 are observed near the edge of the samples, and the minima of N1 and EL2 concentration lie between the center and the edge of the sample. It seems that these spatial variations of N1 and EL2 concentration are consistent with that of the thermal stress induced by RTP. Furthermore, the EL2 concentration near the edge of the sample is suppressed by the contact with the GaAs pieces on the edge around the sample during RTP.


1998 ◽  
Vol 510 ◽  
Author(s):  
D.Z. Chi ◽  
S. Ashok ◽  
D. Theodore

AbstractThermal evolution of ion implantation-induced defects and the influence of concurrent titanium silicidation in pre-amorphized p-type Si (implanted with 25 KeV, 1016 cm2Si+) under rapid thermal processing (RTP) have been investigated. Presence of implantation-induced electrically active defects has been confirmed by current-voltage (IV) and deep level transient spectroscopy (DLTS) measurements. DLTS characterization results show that the evolution of electrically active defects in the Si implanted samples under RTP depend critically on the RTP temperature: Hole traps HI (0.33 eV) and H4 (0.47 eV) appear after the highest temperature (950 °C) anneal, while a single trap H3 (0.26 eV) shows up at lower anneal temperatures (≤ 900 °C). The thermal signature of H4 defect is very similar to that of the iron interstitial while those of HI and H3 levels appear to originate from some interstitial-related defects, possibly complexes. A most interesting finding is that the above interstitial related defects can be eliminated completely with Ti silicidation, apparently a result of vacancy injection. However the silicidation process itself introduces a new H2 (0.30 eV) level, albeit at much lower concentration. This same H2 level is also seen in unimplanted samples under RTP. The paper will present details of defect evolution under various conditions of RTP for samples with and without the self-implantation and silicidation.


1989 ◽  
Vol 146 ◽  
Author(s):  
A. Ito ◽  
A. Kitagawa ◽  
Y. Tokuda ◽  
A. Usami ◽  
H. Kano ◽  
...  

ABSTRACTVariations of electron traps in molecular-beam-epitaxial (MBE) GaAs layers grown on Si substrates by rapid thermal processing (RTP) have been investigated with deep level transient spectroscopy (DLTS). RTP was performed at 760 – 910 °C for 9s with Si02 encapsulant. In contrast with the layer on GaAs, the traps AI(Ec – 0.65eV) and A2(Ec – 0.81eV) are observed in the layer on Si. The trap EL2h, one of the EL2 family, is produced by RTP in the layer on Si. Some GaAs surfaces were etched to prove the deeper region. In the surface region, the concentrartion of EL2h is comparable to that of EL2 produced by RTP in the layer on GaAs. On the other hand, in ∿ 1 μm below the surface, the concentration of EL2h is about ten times as large as that of EL2. It is speculated that the stress from the GaAs/Si interface enhances the production of the EL2h concentration. In addition to the EL2, the traps R1(Ec – 0.23 eV), R2(Ec – 0.40 eV), R3(Ec – 0.43eV) and R4(Ec – 0.56 eV) are produced by RTP in the GaAs grown on Si.


1996 ◽  
Vol 428 ◽  
Author(s):  
R. Beyer ◽  
H. Burghardt ◽  
R. Reich ◽  
E. Thomas ◽  
D. Grambole ◽  
...  

AbstractSiliconoxynitride layers with thicknesses between 5 and 10 nm were grown on (100) oriented silicon by rapid thermal processing (RTP) using either N2O or NH3 as nitridant. In order to study the trapping behaviour at the interface and in the insulator bulk, capacitance-voltage (CV) and current-voltage (IV) measurements have been performed combined with different magnitudes of Fowler-Nordheim stress. In addition, Deep Level Transient Spectroscopy (DLTS) has been applied for interface state detection. Auger Electron Spectroscopy (AES) has been used to obtain depth profiles for Si, N, O and C. The deconvolution of the AES signal displays significant peak contributions related to intermedium oxidation states. Nuclear Reaction Analysis (NRA) was successfully applied for hydrogen detection in buried SiOxNy thin films.


1987 ◽  
Vol 92 ◽  
Author(s):  
A. Usami ◽  
Y. Tokuda ◽  
H. Shiraki ◽  
H. Ueda ◽  
T. Wada ◽  
...  

ABSTRACTRapid thermal processing using halogen lamps was applied to the diffusion of Zn into GaAs0.6 P0.4:Te from Zn-doped oxide films. The Zn diffusion coefficient of the rapid thermal diffused (RTD) samples at 800°C for 6 s was about two orders of magnitude higher than that of the conventional furnace diffused samples at 800°C for 60 min. The enhanced diffusion of Zn by RTD may be ascribed to the stress field due to the difference in the thermal expansion coefficient between the doped oxide films and GaAs0.6P0.4 materials, and due to the temperature gradient in GaAs0.6P0 4 materials. The Zn diffusion coefficient at Zn concentration of 1.0 × l018 cm−3 was 3.6 × 10−11, 3.1 × 10−11 and 5.0 × 10−12 cm2 /s for the RTD samples at 950°C for 6 s from Zn-, (Zn,Ga)- and (Zn,P)-doped oxide films, respectively. This suggests that Zn diffusibility was controlled by the P in the doped oxide films.


1987 ◽  
Vol 62 (2) ◽  
pp. 528-533 ◽  
Author(s):  
Masayuki Katayama ◽  
Akira Usami ◽  
Takao Wada ◽  
Yutaka Tokuda

2008 ◽  
Vol 1068 ◽  
Author(s):  
Tsuneo Ito ◽  
Yutaka Terada ◽  
Takashi Egawa

ABSTRACTDeep level electron traps in n-GaN grown by metal organic vapor phase epitaxy (MOVPE) on Si (111) substrate were studied by means of deep level transient spectroscopy (DLTS). The growth of n-GaN on different pair number of AlN/GaN superlattice buffer layers (SLS) system and on c-face sapphire substrate are compared. Three deep electron traps labeled E4 (0.7-0.8 eV), E5 (1.0-1.1 eV), were observed in n-GaN on Si substrate. And the concentrations of these traps observed for n-GaN on Si are very different from that on sapphire substrate. E4 is the dominant of these levels for n-GaN on Si substrate, and it behaves like point-defect due to based on the analysis by electron capture kinetics, in spite of having high dislocation density of the order of 1010 cm−3.


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