Empirical Model for Electrical Activation of Aluminum- and Boron-Implanted Silicon Carbide
04 Jan 2018-IEEE Transactions on Electron Devices (Institute of Electrical and Electronics Engineers (IEEE))-Vol. 65, Iss: 2, pp 674-679
TL;DR: In this paper, an empirical model for the electrical activation of aluminum and boron impurities in silicon carbide for various annealing temperatures and total doping concentrations is proposed.
Abstract: Accurate modeling of the electrical properties of impurities in semiconductors is essential for the mandatory support of the development of novel semiconductor devices by means of simulations. An appropriate modeling approach to determine the activation rate of dopants in silicon carbide is currently not available, which limits the predictability of process simulations. To remedy this fact, we propose an empirical model for the electrical activation of aluminum and boron impurities in silicon carbide for various annealing temperatures and total doping concentrations. The differences of the two acceptor-type dopants are discussed according to the model predictions and the activation ratios for various processing parameters are presented. The model was implemented into Silvaco’s simulation platform Victory Process and evaluated with respect to published experimental findings.
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TL;DR: An investigation of the silicon and carbon emission is performed with respect to various orientations in order to support further development of macroscopic physical models that aim to predict initial silicon carbide oxidation.
Abstract: We analyze the early stage of the highly anisotropic silicon carbide oxidation behavior with reactive force field molecular dynamics simulations. The oxidation of a-, C,- m-, and Si-crystallographic faces is studied at typical industry-focused temperatures in the range from 900 to 1200 °C based on the time evolution of the oxidation mechanism. The oxide thicknesses and the growth rates are obtained from these simulation results. In addition, an investigation of the silicon and carbon emission is performed with respect to various orientations in order to support further development of macroscopic physical models that aim to predict initial silicon carbide oxidation.
21 citations
TL;DR: In this paper, a transient model for electrical activation of implanted aluminium and phosphorus in silicon carbide was introduced to fill the gap of accurate description of the electrical properties of impurities.
Abstract: The development of novel electron devices requires a continuous support by process and device simulations in order to improve electrical properties and reduce production costs. However, an accurate description of the electrical properties of impurities in silicon carbide – a key wide bandgap semiconductor for power devices – is currently not available, which significantly limits the predictability of critical fabrication processes. Here, we introduce a transient model for electrical activation of implanted aluminium and phosphorus in silicon carbide to fill this gap. Our results suggest differences between acceptor- and donor-type dopants including activation speed, saturation limit, and activation regions. We predict acceptor and donor concentrations according to the various annealing times, temperatures, and doping concentrations. The results are used for the fabrication of PN-junction diodes, which are characterized and compared with the experimental findings. Finally, we predict improvements of variou...
14 citations
TL;DR: In this article, the authors developed two extended models by adding an additional acceptor-or donor-like defect to the neutrality equation and showed that an additional aluminum-correlated acceptor is the more reasonable choice.
Abstract: In 4H silicon carbide, aluminum implantation causes unusual high compensation ratios as obtained from Hall effect investigations by fitting the neutrality equation with a single acceptor. We show that this approach cannot fully describe the experimental data, in particular in case of moderate doping and at high measurement temperatures above 450 K. We develop two extended models by adding an additional acceptor- or donor-like defect to the equation. Both approaches describe the data well. However, it turns out that an additional aluminum-correlated acceptor is the more reasonable choice. In this case, the compensation ratio stays almost independent of the implantation dose between 30 % and 40 %. The deep acceptor is located at EV + (280–400) meV.
9 citations
TL;DR: In this article, the effects of postimplantation annealing on the electrical characteristics of silicon carbide-based double-implanted metaloxide-semiconductor field effect transistors are analyzed.
Abstract: Technological control of doped regions is exceptionally important for all semiconductor devices. For the wide bandgap semiconductor silicon carbide, the activation state of dopants is determined by the postimplantation annealing step which consequently affects device operation and characteristics. We perform a detailed analysis of the effects of postimplantation annealing on the electrical characteristics of silicon carbide-based double-implanted metal–oxide–semiconductor field-effect transistors. We predict acceptor and donor concentrations according to various annealing times, temperatures, and total doping concentrations. The findings are used as a basis for the combined process and device simulations, providing the capability to characterize a reference device and predict the annealing dependence of output and transfer characteristics. Our results are in excellent agreement with the experiments and show precisely how annealing steps influence channel potential, drain current, ON-state resistance, and threshold voltage. Finally, we predict device characteristics based on the annealing variables, showing a high sensitivity of the threshold voltage on annealing time and temperature.1
5 citations
Cites background or methods from "Empirical Model for Electrical Acti..."
...The most widely used technology for selective doping of SiC is ion implantation [6]–[8], which requires a postimplantation annealing treatment in order to repair crystal defects and to increase the activation of dopants [2], [9]....
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...One of the general implantation-related issues of SiC is that the rate of the dopant activation after high dose implantation (above 1018 cm−3) decreases significantly [2], [17], that is, saturates, which limits the achievable ratio of electrical activation....
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...However, fabricating SiC devices is very challenging: many processes are not fully understood [2], which prevents...
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TL;DR: In this article , a 2kV SiC super-junction (SJ) PiN diodes formed by deep implantation of Al and N are presented. But their performance is limited to a 10μm pitch with a measured blocking voltage 500V higher than comparable SiC non-SJ diode.
Abstract: We report successful demonstration of 2kV, SiC super-junction (SJ) PiN diodes formed by deep implantation of Al and N. In our devices, alternating 12μm deep n-type and p-type SJ pillars fabricated on a 10μm pitch and result in a SJ diode with a measured blocking voltage 500V higher than comparable non-SJ diodes. Four activation anneals ranging from 1700 °C to 2000 °C were compared for effectiveness in eliminating post-implant lattice damage, and the optimum anneal condition was identified.
4 citations
References
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Book•
06 May 2013
TL;DR: In this paper, the authors present a discussion of whether, if, how, and when a moderate mediator can be used to moderate another variable's effect in a conditional process analysis.
Abstract: I. FUNDAMENTAL CONCEPTS 1. Introduction 1.1. A Scientist in Training 1.2. Questions of Whether, If, How, and When 1.3. Conditional Process Analysis 1.4. Correlation, Causality, and Statistical Modeling 1.5. Statistical Software 1.6. Overview of this Book 1.7. Chapter Summary 2. Simple Linear Regression 2.1. Correlation and Prediction 2.2. The Simple Linear Regression Equation 2.3. Statistical Inference 2.4. Assumptions for Interpretation and Statistical Inference 2.5. Chapter Summary 3. Multiple Linear Regression 3.1. The Multiple Linear Regression Equation 3.2. Partial Association and Statistical Control 3.3. Statistical Inference in Multiple Regression 3.4. Statistical and Conceptual Diagrams 3.5. Chapter Summary II. MEDIATION ANALYSIS 4. The Simple Mediation Model 4.1. The Simple Mediation Model 4.2. Estimation of the Direct, Indirect, and Total Effects of X 4.3. Example with Dichotomous X: The Influence of Presumed Media Influence 4.4. Statistical Inference 4.5. An Example with Continuous X: Economic Stress among Small Business Owners 4.6. Chapter Summary 5. Multiple Mediator Models 5.1. The Parallel Multiple Mediator Model 5.2. Example Using the Presumed Media Influence Study 5.3. Statistical Inference 5.4. The Serial Multiple Mediator Model 5.5. Complementarity and Competition among Mediators 5.6. OLS Regression versus Structural Equation Modeling 5.7. Chapter Summary III. MODERATION ANALYSIS 6. Miscellaneous Topics in Mediation Analysis 6.1. What About Baron and Kenny? 6.2. Confounding and Causal Order 6.3. Effect Size 6.4. Multiple Xs or Ys: Analyze Separately or Simultaneously? 6.5. Reporting a Mediation Analysis 6.6. Chapter Summary 7. Fundamentals of Moderation Analysis 7.1. Conditional and Unconditional Effects 7.2. An Example: Sex Discrimination in the Workplace 7.3. Visualizing Moderation 7.4. Probing an Interaction 7.5. Chapter Summary 8. Extending Moderation Analysis Principles 8.1. Moderation Involving a Dichotomous Moderator 8.2. Interaction between Two Quantitative Variables 8.3. Hierarchical versus Simultaneous Variable Entry 8.4. The Equivalence between Moderated Regression Analysis and a 2 x 2 Factorial Analysis of Variance 8.5. Chapter Summary 9. Miscellaneous Topics in Moderation Analysis 9.1. Truths and Myths about Mean Centering 9.2. The Estimation and Interpretation of Standardized Regression Coefficients in a Moderation Analysis 9.3. Artificial Categorization and Subgroups Analysis 9.4. More Than One Moderator 9.5. Reporting a Moderation Analysis 9.6. Chapter Summary IV. CONDITIONAL PROCESS ANALYSIS 10. Conditional Process Analysis 10.1. Examples of Conditional Process Models in the Literature 10.2. Conditional Direct and Indirect Effects 10.3. Example: Hiding Your Feelings from Your Work Team 10.4. Statistical Inference 10.5. Conditional Process Analysis in PROCESS 10.6. Chapter Summary 11. Further Examples of Conditional Process Analysis 11.1. Revisiting the Sexual Discrimination Study 11.2. Moderation of the Direct and Indirect Effects in a Conditional Process Model 11.3. Visualizing the Direct and Indirect Effects 11.4. Mediated Moderation 11.5. Chapter Summary 12. Miscellaneous Topics in Conditional Process Analysis 12.1. A Strategy for Approaching Your Analysis 12.2. Can a Variable Simultaneously Mediate and Moderate Another Variable's Effect? 12.3. Comparing Conditional Indirect Effects and a Formal Test of Moderated Mediation 12.4. The Pitfalls of Subgroups Analysis 12.5. Writing about Conditional Process Modeling 12.6. Chapter Summary Appendix A. Using PROCESS Appendix B. Monte Carlo Confidence Intervals in SPSS and SAS
26,144 citations
"Empirical Model for Electrical Acti..." refers methods in this paper
...We have performed several iterations of least squares fitting method [24] to ensure minimal numerical error....
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Book•
23 Sep 2014
TL;DR: A comprehensive introduction and up-to-date reference to SiC power semiconductor devices covering topics from material properties to applications is provided in this paper. But the authors focus on the SiC Schottky barrier diodes (SBDs) and do not provide an in-depth reference for scientists and engineers working in this field.
Abstract: A comprehensive introduction and up-to-date reference to SiC power semiconductor devices covering topics from material properties to applications Based on a number of breakthroughs in SiC material science and fabrication technology in the 1980s and 1990s, the first SiC Schottky barrier diodes (SBDs) were released as commercial products in 2001. The SiC SBD market has grown significantly since that time, and SBDs are now used in a variety of power systems, particularly switch-mode power supplies and motor controls. SiC power MOSFETs entered commercial production in 2011, providing rugged, high-efficiency switches for high-frequency power systems. In this wide-ranging book, the authors draw on their considerable experience to present both an introduction to SiC materials, devices, and applications and an in-depth reference for scientists and engineers working in this fast-moving field . Fundamentals of Silicon Carbide Technology covers basic properties of SiC materials, processing technology, theory and analysis of practical devices, and an overview of the most important systems applications. Specifically included are:
658 citations
"Empirical Model for Electrical Acti..." refers background in this paper
...S ILICON carbide (SiC) is a wide bandgap semiconductor with outstanding properties, such as high thermal conductivity, high electrical breakdown field, high temperature operation, and low reverse leakage current [1], [2]....
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TL;DR: In this article, an isolated on-board vehicular battery charger that utilizes silicon carbide (SiC) power devices to achieve high density and high efficiency for application in electric vehicles (EVs) and plug-in hybrid EVs (PHEVs).
Abstract: This paper presents an isolated on-board vehicular battery charger that utilizes silicon carbide (SiC) power devices to achieve high density and high efficiency for application in electric vehicles (EVs) and plug-in hybrid EVs (PHEVs). The proposed level 2 charger has a two-stage architecture where the first stage is a bridgeless boost ac-dc converter and the second stage is a phase-shifted full-bridge isolated dc-dc converter. The operation of both topologies is presented and the specific advantages gained through the use of SiC power devices are discussed. The design of power stage components, the packaging of the multichip power module, and the system-level packaging is presented with a primary focus on system density and a secondary focus on system efficiency. In this work, a hardware prototype is developed and a peak system efficiency of 95% is measured while operating both power stages with a switching frequency of 200 kHz. A maximum output power of 6.1 kW results in a volumetric power density of 5.0 kW/L and a gravimetric power density of 3.8 kW/kg when considering the volume and mass of the system including a case.
355 citations
"Empirical Model for Electrical Acti..." refers background in this paper
...Due to these attractive properties, SiC has been used in a series of promising applications for low-loss, high-power, and highfrequency electronic devices capable of operating in harsh environments [3]–[5]....
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TL;DR: In this article, aluminum and boron implantation in 4H/6H SiC was investigated, and the degree of electrical activity of implanted Al/B atoms was determined as a function of the annealing temperature.
Abstract: Experimental studies on aluminum (Al) and boron (B) implantation in 4H/6H SiC are reported; the implantation is conducted at room temperature or elevated temperatures (500 to 700 C). Both Al and B act as ``shallow`` acceptors in SiC. The ionization energy of these acceptors, the hole mobility and the compensation in the implanted layers are obtained from Hall effect investigations. The degree of electrical activity of implanted Al/B atoms is determined as a function of the annealing temperature. Energetically deep centers introduced by the Al{sup +}/B{sup +} implantation are investigated. The redistribution of implanted Al/B atoms subsequent to anneals and extended lattice defects are monitored. The generation of the B-related D-center is studied by coimplantation of Si/B and C/B, respectively. (orig.) 60 refs.
271 citations
"Empirical Model for Electrical Acti..." refers background or result in this paper
...[19], and solid lines refer to the reproduced and predicted results obtained in this paper....
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...[19] in order to enable an elaborate comparison....
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...[19], which consists of a nitrogen-doped, n-type SiC wafer with a compensation concentration of ≈1....
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01 Jan 2002
TL;DR: Zetterling, S.M.Ostling and S.J.Pearton as mentioned in this paper, S.Sveinbjornsson, S.-K.Lee, and M.
Abstract: Introduction 1 Advantages of SiC C.-M.Zetterling and M.Ostling 2 Bulk and epitaxial growth of SiC N.Nordell 3 Ion implantation and diffusion in SiC A.Schoner 4 Wet and dry etching of SiC S.J.Pearton 5 Thermally grown and deposited thermoelectrics E.O.Sveinbjornsson and C.-M.Zetterling 6 Schottky and ohmic contacts to SiC C.-M.Zetterling, S.-K.Lee and M.Ostling 7 Devices in SiC C.-M.Zetterling, S.M.Koo and M.Ostling Appendix 1: Other resources Appendix 2: Glossary Index
218 citations
"Empirical Model for Electrical Acti..." refers methods in this paper
...These plots were then fit with the charge neutrality equation [22] to obtain Al and B acceptor concentrations using the thermal ionization energy as a fitting parameter, shown in our previous study [23]....
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