Boron and phosphorous implantation into (100) germanium : modeling and investigation of dopant annealing behavior

Germanium is increasingly being considered at this time for future silicon compatible optoelectronic and complementary metal oxide semiconductor (CMOS) device application. Germanium implantation will be a critical process for future device fabrication. However, critical properties like Pearson parameters and dopant activation temperatures are not well established. In this study, boron and phosphorus were implanted into (100) germanium with energies ranging from 20 to 320 keV and doses of 5 x 1013 to 5 x 1016 cm-2. The behavior of the boron and phosphorus before and after annealing for 3 hours at 400, 600 or 800°C in ultra high purity nitrogen were characterized using secondary ion mass spectrometry (SIMS), spreading resistance profiling (SRP) measurements, Hall Effect measurement, X-ray diffraction (XRD) measurement, and Rutherford backscattering spectrometry (RB S). A predictive model for the implanted dopant distribution\u27s dependence on energy was developed using the experimentally determined implant moments combined with Pearson distributions and the post-annealing electrical, structural and diffusion behavior was characterized. Results from numeric simulation and analytic calculations using Lindard-Scharff-Schiott (LSS) theory are presented to offer insight into the physics of the pre-annealed implanted dopant distributions

Hierarchical Coding for Distributed Computing

Coding for distributed computing supports low-latency computation by relieving the burden of straggling workers. While most existing works assume a simple master-worker model, we consider a hierarchical computational structure consisting of groups of workers, motivated by the need to reflect the architectures of real-world distributed computing systems. In this work, we propose a hierarchical coding scheme for this model, as well as analyze its decoding cost and expected computation time. Specifically, we first provide upper and lower bounds on the expected computing time of the proposed scheme. We also show that our scheme enables efficient parallel decoding, thus reducing decoding costs by orders of magnitude over non-hierarchical schemes. When considering both decoding cost and computing time, the proposed hierarchical coding is shown to outperform existing schemes in many practical scenarios.Comment: 7 pages, part of the paper is submitted to ISIT201

CRM Strategies for A Small-Sized Online Shopping Mall Based on Association Rules and Sequential Patterns

Data mining has a tremendous contribution to the extraction of knowledge and information which have been hidden in a large volume of data. This study has proposed customer relationship management (CRM) strategies for a small-sized online shopping mall based on association rules and sequential patterns obtained by analyzing the transaction data of the shop. We first defined the VIP customer in terms of recency, frequency and monetary value. Then, we developed a model which classifies customers into VIP or non-VIP, using various techniques such as decision tree, artificial neural network and bagging with each of these as a base classifier. Last, we identified association rules and sequential patterns from the transactions of VIPs, and then these rules and patterns were utilized to propose CRM strategies for the online shopping mall

Health Diagnosis of Communities of Practices (CoPs)

The purpose of this study is to provide a multi-level framework to diagnose the structural healthiness of CoPs and present a new metric, Bottleneck Impact Score (BIS), to measure the seriousness of bottlenecks in knowledge sharing activities among CoPs members. After analyzing knowledge sharing activities of 4,414 members from 59 CoPs, we confirm that while only a small number of CoP members actively engage in both transferring and receiving knowledge, most experts are not core players and they are reluctant to share their knowledge with others. We also find that only few CoPs can be classified as knowledge “sharing” community while most of CoPs suffer from inactive participation of employees with high expertise and are diagnosed as having at least one of master-apprenticeship and knowledge drain bottlenecks. Interestingly, we also find that CoPs members in field division such as Iron&Steel, Rolling, and Maintenance department more actively participate in knowledge sharing than CoPs members in Staff department. Finally, BISs are used to measure and compare the seriousness of six different types of bottlenecks in CoPs and departments

Toward Optimal Financial Reward Allocation for Promoting Knowledge Sharing Activity in CoPs

The purpose of this study is to introduce CoP reward allocation (COREA) system that efficiently solves a mathematical optimization problem to optimally allocate limited financial reward and to promote knowledge sharing activities in CoPs. To test the validity and usefulness of COREA, we simulate three knowledge sharing climates in which the majority of CoPs performs below-, on-, or above-average. In addition, we also allow knowledge sharing activity of CoPs to improve or deteriorate over years in each climate. Our experimental results confirm that the proposed COREA system performs significantly better than the currently available reward system over various scenarios. In particular, the COREA system finds approximately optimal financial reward allocations for many cases in which the current reward system fails to find solutions that meet constraints

Al2O3/TiO2 stack layers for effective surface passivation of crystalline silicon

For silicon surface passivation, we investigate stack layers consisting of a thin Al₂O₃ layer and a TiO₂capping layer deposited by means of thermal atomic layer deposition (ALD). In this work, we studied the influence of different thermal post-deposition treatments and film thickness for the activation of passivating ALD Al₂O₃ single layers and Al₂O₃/TiO₂ stack layers. Our experiments show a substantial improvement of the passivation for the Al₂O₃/TiO₂ stack layers compared to a thin single Al₂O₃ layer. For the stacks, especially with less than 10 nm Al₂O₃, a TiO₂capping layer results in a remarkably lower surface recombination. Effective fixed charge density of Al₂O₃/TiO₂ stack layers increases after TiO₂deposition and O₂ annealing. It is also demonstrated that the enhanced surface passivation can be mainly related to a remarkably low interface defect density of 1.1 × 10¹⁰ eV¯¹ cm¯², whereas post-TiO₂ heat treatment in O₂ ambience is not beneficial for the passivation of silicon, which is attributed to increasing interface defect density of stack layers.This project has been supported by the Australian Government through the Australian Solar Institute, part of the Clean Energy Initiative