Dry Etching Damage Effect on Ohmic Characteristics of GaN

MRS Proceedings ◽

10.1557/proc-512-495 ◽

1998 ◽

Vol 512 ◽

Author(s):

Jin Seok Khim ◽

Taek Kim ◽

Su Hee Chae ◽

Tae Il Kim ◽

Hyon-Soo Kim ◽

...

Keyword(s):

Chemical Vapor ◽

Dry Etching ◽

Shallow Donor ◽

Etching Process ◽

Damage Effect ◽

Transmission Line Method ◽

Specific Contact ◽

Rapid Thermal Annealer ◽

The Difference ◽

The One

ABSTRACTWe report on the dry etching damage effects on the Ohmic contact characteristics of Sidoped n-type GaN. The 2-µm thick n-type GaN samples whose carrier concentrations are ∼7 × 1017/cm3 are grown on c-plane sapphire substrates by metalorganic chemical vapor deposition(MOCVD). The samples are processed to measure the transmission line method(TLM). We evaporated Ti/Al/Ni/Au=150/2700/400/4000 Å on the samples using an ebeam evaporator under 5 × 10−7 torr and annealed at 700 °C for lminute using a rapid thermal annealer(RTA). AES and XPS data show that the surface stoichiometry of the sample etched with H2 gas is gallium- richer than that of the one etched with Cl2 gas. According to the previous report[l], N-vacancy acts as shallow donor in GaN. However, specific contact resistivity of the sample etched with H2 gas is 3.03 × 10−6 Ω cm 2, which is much higher than that of the sample etched with C12 gas, 7.9 × 10 −7 Ω cm2. The difference of the N- vacancy formed during the etching process cannot completely explain the result. We suggest that formation of GaxOy during etching process, and the weakening of the bonding by ion bombardments might be responsible for the difference in the ohmic characteristics.

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Characterization of Electrical Contacts on Polycrystalline 3C-SiC Thin Films

Materials Science Forum ◽

10.4028/www.scientific.net/msf.483-485.745 ◽

2005 ◽

Vol 483-485 ◽

pp. 745-748

Author(s):

Antonio Castaldini ◽

Anna Cavallini ◽

Marco Rossi ◽

M. Cocuzza ◽

C. Ricciardi

Keyword(s):

Thin Films ◽

Electrical Properties ◽

Pressure Sensors ◽

Chemical Vapor ◽

Electrical Contacts ◽

Transmission Line Method ◽

Specific Contact ◽

Pressure Chemical ◽

Different Temperatures ◽

Micro Electromechanical System

We report on the investigation of electrical properties of polycrystalline 3C-SiC thin films deposited on oxidized Si by low pressure chemical vapor deposition (LPCVD) to obtain bi-layer structures [Si(100)/SiO2/poly 3C-SiC] for pressure sensors and micro-electromechanical system (MEMS) applications. Polycrystalline 3C-SiC films have been preliminary characterized in their compositional, structural, morphological and electrical properties. Moreover, metal contact definition has been carefully optimized by transmission line method (TLM) analyses performed at different temperatures. We focuses the attention on the evaluation of the bulk resistivity (ρ), the specific contact resistivity (ρc) and their behavior dependence on the temperature because these are the characteristics of major importance for the fabrication of pressure sensors or MEMS.

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STM studies of crystal growth

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100086179 ◽

1991 ◽

Vol 49 ◽

pp. 374-375

Author(s):

M. G. Lagally

Keyword(s):

Crystal Growth ◽

Molecular Beam ◽

Chemical Vapor ◽

Sputter Deposition ◽

Field Of View ◽

Scanning Tunneling ◽

Wide Field ◽

Tunneling Microscopy ◽

Wide Field Of View ◽

The One

It has been recognized since the earliest days of crystal growth that kinetic processes of all Kinds control the nature of the growth. As the technology of crystal growth has become ever more refined, with the advent of such atomistic processes as molecular beam epitaxy, chemical vapor deposition, sputter deposition, and plasma enhanced techniques for the creation of “crystals” as little as one or a few atomic layers thick, multilayer structures, and novel materials combinations, the need to understand the mechanisms controlling the growth process is becoming more critical. Unfortunately, available techniques have not lent themselves well to obtaining a truly microscopic picture of such processes. Because of its atomic resolution on the one hand, and the achievable wide field of view on the other (of the order of micrometers) scanning tunneling microscopy (STM) gives us this opportunity. In this talk, we briefly review the types of growth kinetics measurements that can be made using STM. The use of STM for studies of kinetics is one of the more recent applications of what is itself still a very young field.

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Use of a Lyophilized Reference Plasma to Compare Coagulation Test Procedures

Thrombosis and Haemostasis ◽

10.1055/s-0038-1651402 ◽

1975 ◽

Vol 34 (02) ◽

pp. 426-444 ◽

Cited By ~ 3

Author(s):

J Kahan ◽

I Nohén

Keyword(s):

Oral Anticoagulant Therapy ◽

Repeated Measurements ◽

Test Procedures ◽

Coagulation Activity ◽

Close Relationship ◽

Measured Activity ◽

Test Materials ◽

The Difference ◽

The Stability ◽

The One

SummaryIn 4 collaborative trials, involving a varying number of hospital laboratories in the Stockholm area, the coagulation activity of different test materials was estimated with the one-stage prothrombin tests routinely used in the laboratories, viz. Normotest, Simplastin-A and Thrombotest. The test materials included different batches of a lyophilized reference plasma, deep-frozen specimens of diluted and undiluted normal plasmas, and fresh and deep-frozen specimens from patients on long-term oral anticoagulant therapy.Although a close relationship was found between different methods, Simplastin-A gave consistently lower values than Normotest, the difference being proportional to the estimated activity. The discrepancy was of about the same magnitude on all the test materials, and was probably due to a divergence between the manufacturers’ procedures used to set “normal percentage activity”, as well as to a varying ratio of measured activity to plasma concentration. The extent of discrepancy may vary with the batch-to-batch variation of thromboplastin reagents.The close agreement between results obtained on different test materials suggests that the investigated reference plasma could be used to calibrate the examined thromboplastin reagents, and to compare the degree of hypocoagulability estimated by the examined PIVKA-insensitive thromboplastin reagents.The assigned coagulation activity of different batches of the reference plasma agreed closely with experimentally obtained values. The stability of supplied batches was satisfactory as judged from the reproducibility of repeated measurements. The variability of test procedures was approximately the same on different test materials.

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The Demand For Money in Pakistan: Reply (Notes and Comments)

The Pakistan Development Review ◽

10.30541/v14i3pp.370-375 ◽

1975 ◽

Vol 14 (3) ◽

pp. 370-375

Author(s):

M. A. Akhtar

Keyword(s):

Interest Rates ◽

Money Demand ◽

Strong Support ◽

Physical Capital ◽

Careful Examination ◽

Demand For Money ◽

Weak Support ◽

Complementarity Hypothesis ◽

The Difference ◽

The One

I am grateful to Abe, Fry, Min, Vongvipanond, and Yu (hereafter re¬ferred to as AFMVY) [1] for obliging me to reconsider my article [2] on the demand for money in Pakistan. Upon careful examination, I find that the AFMVY results are, in parts, misleading and that, on the whole, they add very little to those provided in my study. Nevertheless, the present exercise as well as the one by AFMVY is useful in that it furnishes us with an opportunity to view some of the fundamental problems involved in an empi¬rical analysis of the demand for money function in Pakistan. Based on their elaborate critique, AFMVY reformulate the two hypo¬theses—the substitution hypothesis and the complementarity hypothesis— underlying my study and provide us with some alternative estimates of the demand for money in Pakistan. Briefly their results, like those in my study, indicate that income and interest rates are important in deter¬mining the demand for money. However, unlike my results, they also suggest that the price variable is a highly significant determinant of the money demand function. Furthermore, while I found only a weak support for the complementarity between money demand and physical capital, the results obtained by AFMVY appear to yield a strong support for that rela¬tionship.1 The difference in results is only a natural consequence of alter¬native specifications of the theory and, therefore, I propose to devote most of this reply to the criticisms raised by AFMVY and the resulting reformulation of the two mypotheses.

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Effect of leakage and blockage on the acoustic behavior of particle filters

Noise Control Engineering Journal ◽

10.3397/1/376744 ◽

2019 ◽

Vol 67 (6) ◽

pp. 483-492

Author(s):

Seonghyeon Baek ◽

Iljae Lee

Keyword(s):

Transfer Matrix ◽

Particle Filters ◽

Acoustic Analysis ◽

Transmission Loss ◽

One Dimensional ◽

Filter System ◽

The Difference ◽

The One ◽

Analytical Approaches ◽

Good Agreement

The effects of leakage and blockage on the acoustic performance of particle filters have been examined by using one-dimensional acoustic analysis and experimental methods. First, the transfer matrix of a filter system connected to inlet and outlet pipes with conical sections is measured using a two-load method. Then, the transfer matrix of a particle filter only is extracted from the experiments by applying inverse matrices of the conical sections. In the analytical approaches, the one-dimensional acoustic model for the leakage between the filter and the housing is developed. The predicted transmission loss shows a good agreement with the experimental results. Compared to the baseline, the leakage between the filter and housing increases transmission loss at a certain frequency and its harmonics. In addition, the transmission loss for the system with a partially blocked filter is measured. The blockage of the filter also increases the transmission loss at higher frequencies. For the simplicity of experiments to identify the leakage and blockage, the reflection coefficients at the inlet of the filter system have been measured using two different downstream conditions: open pipe and highly absorptive terminations. The experiments show that with highly absorptive terminations, it is easier to see the difference between the baseline and the defects.

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Development and Validation of Spectrophotometric and Liquid Chromatographic Methods for Estimation of Tigecycline in Injections

International Journal of Pharmaceutical Sciences and Nanotechnology ◽

10.37285/ijpsn.2020.13.5.12 ◽

2020 ◽

Vol 13 (5) ◽

pp. 5148-5154

Author(s):

Sagar Suman Panda ◽

Ravi Kumar B.V.V.

Keyword(s):

Area Under The Curve ◽

Reversed Phase ◽

Equal Concentration ◽

Pharmaceutical Dosage Form ◽

Liquid Chromatographic Method ◽

Array Detection ◽

The Difference ◽

The One ◽

Development And Validation ◽

Liquid Chromatographic

Three new analytical methods were optimized and validated for the estimation of tigecycline (TGN) in its injection formulation. A difference UV spectroscopic, an area under the curve (AUC), and an ultrafast liquid chromatographic (UFLC) method were optimized for this purpose. The difference spectrophotometric method relied on the measurement of amplitude when equal concentration solutions of TGN in HCl are scanned against TGN in NaOH as reference. The measurements were done at 340 nm (maxima) and 410nm (minima). Further, the AUC under both the maxima and minima were measured at 335-345nm and 405-415nm, respectively. The liquid chromatographic method utilized a reversed-phase column (150mm×4.6mm, 5µm) with a mobile phase of methanol: 0.01M KH2PO4 buffer pH 3.5 (using orthophosphoric acid) in the ratio 80:20 %, v/v. The flow rate was 1.0ml/min, and diode array detection was done at 349nm. TGN eluted at 1.656min. All the methods were validated for linearity, precision, accuracy, stability, and robustness. The developed methods produced validation results within the satisfactory limits of ICH guidance. Further, these methods were applied to estimate the amount of TGN present in commercial lyophilized injection formulations, and the results were compared using the One-Way ANOVA test. Overall, the methods are rapid, simple, and reliable for routine quality control of TGN in the bulk and pharmaceutical dosage form.

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Managing the Era of Multi-Cultural Leadership

Purushartha - A Journal of Management Ethics and Spirituality ◽

10.21844/pajmes.v11i1.14610 ◽

2018 ◽

Vol 11 (1) ◽

Author(s):

M. Rahul ◽

R. Ganesan

Keyword(s):

Work Environment ◽

Leadership Style ◽

Work Experience ◽

Cross Culture ◽

Cultural Leadership ◽

Team Members ◽

Diverse Workforce ◽

The Difference ◽

The One ◽

Global Arena

Leaders in the global arena are the one who face the challenges never seen before, while coordinating work and managing relationship between team members coming from varied ethnic groups. Globalization has undoubtedly opened up endless growth opportunities for both, businesses and individuals, by collaborating with each other, but with certain inherent challenges. These challenges are the difference in the cultural background of the team members, which gets predominantly reflected in their behavior at workplace too. The cultural differences exist primarily due to differences in shared values, which form the basis for difference in perception and practices of decision making by an individual (Hofstede, 1980). Juana Bordas has rightly described that any business that fails to adapt their leadership style aligning with multi-cultural approach will find it difficult to thrive in a more colorful world. Leadership style has witnessed various facets of changing work environment that has demanded from leaders to modify their approach to adapt along and be effective and survive in the ever-changing environment of business (Bordas,2007).A cross-culture leader plays a significant role in knitting the diverse workforce into an efficient team; which requires a leader to very well understand the various dimensions of culture. This understanding of the leader enables him to learn about blending of leadership styles to address the challenges of such work environment. This paper is an extended work on 'Leadership in Cross-Cultural Environment – A Comparison of Asian and Non-Asian Managers' (Rahul and Ganesan, 2015). The extended research study has identified that enhanced work experience of cross-culture leaders enables them in effective team management, than the rise in designation, as it results in creation of hierarchical distance between the leaders and subordinates.

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Defending the Difference

10.1093/oso/9780198796220.003.0004 ◽

2017 ◽

Keyword(s):

Social Sciences ◽

Natural Sciences ◽

Point Of View ◽

True Nature ◽

Natural Entities ◽

The Social ◽

The World ◽

Methodological Difference ◽

The Difference ◽

The One

Dreyfus argues that there is a basic methodological difference between the natural sciences and the social sciences, a difference that derives from the different goals and practices of each. He goes on to argue that being a realist about natural entities is compatible with pluralism or, as he calls it, “plural realism.” If intelligibility is always grounded in our practices, Dreyfus points out, then there is no point of view from which one can ask about or provide an answer to the one true nature of ultimate reality. But that is consistent with believing that the natural sciences can still reveal the way the world is independent of our theories and practices.

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