• The Korean Journal of Ceramics
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• v.4 no.2
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• pp.90-94
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• 1998

Self diffusion coefficients of $^{67}$Co and impurity diffusion coefficients of $^{51}$Mn and $^{65}$Zn in single crystalline CoO have been measured by applying different radioactive isotopes simultaneously. To compare the residual activity method and the tracer sectioning method we analyzed our tracer diffusion experiments by using both methods simultaneously. According to our experimental results, the diffusion coefficients obtained from both methods are identical within experimental error, demonstrating the relibility of our experimental procedures. The diffusion coefficients of all the isotopes obtained during these test experiments for the methodology are similar in magnitude and show similar dependences on oxygen partial pressure. These first observations indicate that impurity diffusion of Mn and Zn occur via a vacancy mechanism as known for self diffusion of cobalt.

• KIEE International Transactions on Electrophysics and Applications
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• v.5C no.1
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• pp.18-22
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• 2005

We developed a new systematic calibration procedure and applied it to the calibration of the diffusivity, segregation and TED model of the indium impurity. The TED of the indium impurity was studied under 4 different experimental conditions. Although the indium proved to be susceptible to the TED, the RTA was effective in suppressing the TED effect and in maintaining a steep retrograde profile. Just as in the case of boron, indium demonstrated significant oxidation-enhanced diffusion in silicon and its segregation coefficients at the Si/SiO₂ interface were significantly below 1. In contrast, the segregation coefficient of indium decreased as the temperature increased. The accuracy of the proposed technique has been validated by SIMS data and 0.13-㎛ device characteristics such as Vth and Idsat with errors less than 5% between simulation and experiment.

• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.6
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• pp.929-935
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• 1986

In this paper, we describe the physical modelling and numerical aspects of a program called PRECISE(Program for Efficient Calculation of Impurity Profile in Semiconductor by Elimination) which calcualtes a two-dimensional impurity profile in silicon due to diffusion and ion implantation steps. The PRECISE enables rapid prediction of the two-dimensional impurity profile near the mask edge-or the bird's beak during the local oxidation process. This has been developed by modifying the existing one-dimentional simulator, DIFSIM(DIFfusion SIMulator to include models for arsenic diffusion and emitter dip effect which were found out to agree fairly well with the xperimental data.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.370-374
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• 1988

This paper is concerned with the investigation of the impurity redistribution process in a two step diffusion. In integrated circuit technology, two step boron diffusion involving a deposition step followed by a drive-in step in commonly encounted. The drive-in process is usually performed in oxidizing atmosphere resulting in redistribution of impurity (boron) within the semiconductor. This paper proposes a new numerical analysis method; Bounary Element Method to determine impurity profile at the arbitrary point in domain by its coordinate and boundary value.

• Journal of the Semiconductor & Display Technology
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• v.2 no.2
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• pp.5-8
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• 2003

In this study, as Cu diffusion barrier, tantalum nitrides were successfully deposited on Si(100) substrate and $SiO_2$ by plasma assisted atomic layer deposition(PAALD) and thermal ALD, using pentakis (ethylmethlyamino) tantalum (PEMAT) and NH$_3$ as precursors. The TaN films were deposited at $250^{\circ}C$ by both method. The growth rates of TaN films were 0.8${\AA}$/cycle for PAALD and 0.75${\AA}$/cycle for thermal ALD. TaN films by PAALD showed good surface morphology and excellent step coverage for the trench with an aspect ratio of h/w -1.8:0.12 mm but TaN films by thermal ALD showed bad step coverage for the same trench. The density for PAALD TaN was 11g/cmand one for thermal ALD TaN was 8.3g/$cm^3$. TaN films had 3 atomic % carbon impurity and 4 atomic % oxygen impurity for PAALD and 12 atomic % carbon impurity and 9 atomic % oxygen impurity for thermal ALD. The barrier failure for Cu(200 nm)/TaN(10 nm)/$SiO_2$(85 nm)/ Si structure was shown at temperature above $700^{\circ}C$ by XRD, Cu etch pit analysis.

• Journal of the Korean Vacuum Society
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• v.9 no.2
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• pp.150-154
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• 2000

We investigated the quantum well intermixing (QWI) of a compressively strained InGaAs/InGaAsP multiple quantum well (MQW) by using impurity free vacancy diffusion technique. The samples with InGaAs/$SiO_2$ capping layer showed a higher degree of intermixing compared to that of InP/$SiO_2$ capping layer after rapid thermal annealing (RTA). Band-gap shift difference as large as 123 meV (195 nm) was observed between samples capped with InGaAs/$SiO_2$ and with InP/$SiO_2$ layer at RTA temperature of $700^{\circ}C$. Using the InGaAs/$SiO_2$ cap layer, the band-gap wavelength of MQW was changed by the intermixing from 1.55 $\mu\textrm{m}$ band to 1.3 $\mu\textrm{m}$ band with a wavelength shift of a 237 nm. The transform from MQW structure to homogenous alloy was observed above the RTA temperature of $700^{\circ}C$.

• ETRI Journal
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• v.11 no.4
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• pp.84-97
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• 1989

The influence of Zn, Si and Te diffusion on the interdiffusion in $GaAs-Ga_1_-xIN_xAs_1__yP_y$and InP$Ga_1__xIn_xAs_1__yP_y$ heterostructures was studied. The heterostructures were grown by liquid phase epitaxy, and the impurity diffusion into the heterostructures was carried out using metal compound or element sources. The extent of interdiffusion for both group III and V atoms was observed by depth profiling of matrix elements with secondary ion mass spectrometry and Auger electron spectroscopy. Selective enhancement of cation interdiffusion was observed by the concurrent Zn diffusion in both the GaAs based-and InP based-crystals. In contrast to the Zn diffusion, the Si diffusion in the GaAs based-crystal and the Te diffusion in the InP based-crystal enhanced both cation and anion interdiffusion to the same extent. A kick-out mechanism is proposed to explain the selective enhancement of the cation interdiffusion due to Zn, and a single vacancy mechanism is proposed for the interdiffusion due to Si and Te.

• Journal of the Korean Institute of Telematics and Electronics
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• v.21 no.6
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• pp.17-26
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• 1984

A computer program (DIFSIM: Diffusion SIMulator) was written to calculate the impurity profile, specifically boron and phosphorus, due to three different diffusion processes-predeposition, drive-in in inert ambient, and drive-in in oxidizing ambient. The vacancy mechanism including Fair and Tsai's theory for phosphDrus diffusion was widely incorporated for modeling various diffusion processes. The concentrationtependent oxidation rate was also explained using the vacancy model, while the oxidation - enhanced diffusion was mo dolled using catkins replacement mochanlsm . The simulation results using DIFSIM showed a fairly good agreement with the experimental data by adjusting some of the empirical parameters in the program. The results obtained using DIFSIM were compared with the results from SUPREM II.

• Transactions on Electrical and Electronic Materials
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• v.5 no.6
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• pp.211-214
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• 2004

We developed a new systematic calibration procedure which was applied to the calibration of the diffusivity, segregation and TED model of the indium impurity. The TED of the indium impurity has been studied using 4 different groups of experimental conditions. Although the indium is susceptible to the TED, the RTA is effective to suppress the TED effect and maintain a steep retrograde profile. Like the boron, the indium shows significant oxidationenhanced diffusion in silicon and has segregation coefficients at the $Si/SiO_2$ interface much less than 1. In contrast, however, the segregation coefficient of indium decreases as the temperature increases. The accuracy of the proposed technique is validated by SIMS data and $0.13 {\mu}m$ device characteristics such as $V_{th}$ and $Id_{sat}$ with errors less than $5 \%$ between simulation and experiment.

• Proceedings of the Materials Research Society of Korea Conference
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• 1992.05b
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• pp.73-74
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• 1992