Doping Profile Measurements in Silicon Using Terahertz Domain Spectroscopy (THz-TDS) Via Electrochemical Anodic Oxidation

Doping profiles are engineered to manipulate device properties and to determine electrical performances of microelectronic devices frequently. To support engineering studies afterward, essential information is usually required from physically characterized doping profiles. Secondary Ion Mass Spectrometry (SIMS), Spreading Resistance Profiling (SRP) and Electrochemical Capacitance Voltage (ECV) profiling are standard techniques for now to map profile. SIMS yields a chemical doping profile via ion sputtering process and owns a better resolution, whereas ECV and SRP produce an electrical doping profile detecting free carriers in microelectronic devices. The major difference between electrical and chemical doping profiles is at heavily doped regions greater than 1020 atoms/cm3. At the profile region over the solubility limit, inactive dopants induce a flat plateau and detected by electrical measurements only. Destructive techniques are usually designed as stand-alone systems to study impurities. For an in-situ process control purpose, non-contact methods, such as ellipsometry and non-contact capacitance voltage (CV) techniques are current under development. In this theses work, terahertz time domain spectroscopy (THz-TDS) is utilized to achieve electrical doping profile in both destructive and non-contact manners. In recent years the Terahertz group at Rochester Institute Technology developed several techniques that use terahertz pulses to non-destructively map doping profiles. In this thesis, we study a destructive but potentially higher resolution version of the terahertz based approach to map the profile of activated dopants and augment the non-destructive approaches already developed. The basic idea of the profile mapping approach developed in this MS thesis is to anodize, and thus oxidize to silicon dioxide, thin layers (down to below 10 nm) of the wafer with the doping profile to be mapped. Since the dopants atoms and any free carriers in the silicon oxide thin film are invisible to the terahertz probe this anodization step very effectively removes a ‘thin slice’ from the doping profile to be mapped. By iterating between anodization and terahertz measurements that detect only the ‘remaining’ non-oxidized portion of the doping profile one can re-construct the doping profile with significantly higher precision compared to what is possible by only a single non-destructive measurement of the un-anodized profile as used in the non-destructive version of our technique. In this MS thesis we explore all aspects of this anodization based variation of doping profile mapping using free space terahertz pulses. This includes a study of silicon dioxide thin film growth using a room temperature electrochemical oxidation process. Etching procedures providing the option to remove between successive anodization and terahertz measurement steps. THz-TDS measurements of successively anodized profiles will be compared with sheet resistance and SIMS measurements to benchmark and improve the new technique

Fault Tolerant and Fully Dynamic DFS in Undirected Graphs: Simple Yet Efficient

We present an algorithm for a fault tolerant Depth First Search (DFS) Tree in an undirected graph. This algorithm is drastically simpler than the current state-of-the-art algorithms for this problem, uses optimal space and optimal preprocessing time, and still achieves better time complexity. This algorithm also leads to a better time complexity for maintaining a DFS tree in a fully dynamic environment

Static Race Detection for RTOS Applications

We present a static analysis technique for detecting data races in Real-Time Operating System (RTOS) applications. These applications are often employed in safety-critical tasks and the presence of races may lead to erroneous behaviour with serious consequences. Analyzing these applications is challenging due to the variety of non-standard synchronization mechanisms they use. We propose a technique based on the notion of an "occurs-in-between" relation between statements. This notion enables us to capture the interplay of various synchronization mechanisms. We use a pre-analysis and a small set of not-occurs-in-between patterns to detect whether two statements may race with each other. Our experimental evaluation shows that the technique is efficient and effective in identifying races with high precision

Conversion of International Accounting Standards: Taking Indian Accounting Standards into Consideration

ABSTRACT This dissertation is the study of conversion the accounting standards to a global accounting standards i.e. International Financial Regulatory Services. However, the main focus of the study is on the conversion of Indian Accounting Standards to International Accounting Standards. The study also shows the focus on the reactions of the people of India and their knowledge on the International Accounting Standards. It is also gives a knowledge to all the people who is not familiar with IFRS. The research methodology that has been done for this study is the interview questions which has been carried out in India carried out in 10 firms including accounting firms, banks and stock brokerage firms

Feature Match for Medical Images

This paper represents an algorithm for Feature Match, a summed up estimated approximate nearest neighbor field (ANNF) calculation system, between a source and target image. The proposed calculation can estimate ANNF maps between any image sets, not as a matter of course related. This generalization is accomplished through proper spatial-range changes. To register ANNF maps, worldwide shading adjustment is connected as a reach change on the source picture. Image patches from the pair of pictures are approximated utilizing low-dimensional elements, which are utilized alongside KD-tree to appraise the ANNF map. This ANNF guide is further enhanced in view of picture coherency and spatial changes. The proposed generalization, empowers to handle a more extensive scope of vision applications, which have not been handled utilizing the ANNF structure. Here one such application is outlined namely: optic plate discovery .This application manages restorative imaging, where optic circles are found in retinal pictures utilizing a sound optic circle picture as regular target picture. ANNF mappings is used in this application and is shown experimentally that the proposed approaches are faster and accurate, compared with the state-of the-art techniques