Materials for attenuated phase mask application at 193 nm

The electronic revolution is driven by the circuits and devices fabricated on silicon. Since the invention of the integrated circuit some thirty years ago the circuit complexity has increased manifold. A large portion of this increase can be attributed to the ability to print smaller features. The process of printing these small features is termed lithography. The ability to develop new lithographic techniques will determine to a large extent whether the semiconductor industry can maintain its rapid growth rate. Currently lithographic techniques that utilize 193 nm radiation are being developed to replace the 248 nm based lithographic processes. The trend towards smaller features has meant development of optics and materials that can be used at shorter wavelengths. It has also meant the implementation of optical enhancement techniques, to extend the useful lifetime of the available technology. Phase shift technology is currently being developed to extend the useful lifetime of 193 nm based systems. Of the various types of phase shift masks, the attenuated phase shift type seems attractive because they are relatively easy to manufacture. However, at shorter wavelengths the number of materials that can be used as single layer shifters is few. The situation is further aggravated by the additional requirements placed on mask material, such as minimal transmission at alignment wavelength, low resistivity and the ability to be dry etched. The fore-mentioned requirements preclude the use of stoichiometric elements and compounds as materials suitable for a single layer attenuated phase shift mask. However, it may be possible to combine a variety of materials to obtain the desired optical and physical properties. By carefully choosing the absorbing and the non-absorbing components of the material mix, the optical and the physical properties can be engineered to meet the specifications. In case of thin films, the material properties can be varied by adjusting the deposition conditions. For this work reactive sputtering was used to deposit the films. By adjusting the partial pressure, power and time, and through the use of mosaic targets the material properties were investigated. Furthermore, films were also deposited in a layered structure that allowed for a new set of film properties. Several materials were investigated for this work. By following a simple process of elimination the material was first evaluated for its optical properties followed by an evaluation of its physical properties. Films that were investigated were composed of molybdenum silicon oxide, under-stoichiometric aluminum nitride, under-stoichiometric silicon nitride and layered films of tantalum and silicon nitride. The primary selection factor for these films were there optical properties around 193 nm. Following this the films were evaluated for there properties in the visible regime. Finally the films were evaluated for there physical properties, such as stability and volatility of the etched compounds. Only under-stoichiometric aluminum nitride met all the requirements for attenuated phase shift mask material

Effect of Induction Training Program on Teachers’ Effectiveness at Elementary School Level in Punjab

Induction training programs are organized to make teachers familiar with their profession so that they can perform their duties effectively. This study was an exploration of framework of induction training program (ITP) for elementary school educators in Punjab. This qualitative inquiry was based on opinion of all induction training experts and documents related with teachers’ training. The purposively selected sample for this study was five experts of induction training program and documents related with induction training of teachers. Interviews of induction training experts were conducted. Thematic analysis of interviews and documents related with induction training of teachers was conducted. Different themes and coding categories were identified to execute the analysis of responses of induction training experts and documents of induction training. It was concluded from the results that there were five phases of framework of induction training program. First phase was training needs assessment (TNA), second was methodologies, third was training areas, fourth was rationale and fifth was evaluation. There is need to conduct researches on exploration of framework of induction training programs. This will enable different countries to compare their frameworks and enable their teachers to become more effective in accordance with international standards

A Systematic Approach to Quality Oriented Product Sequencing for Multistage Manufacturing Systems

Product sequencing is one way to reduce cost and improve product quality for multistage manufacturing systems (MMS). However, systematically evaluating the influence of product sequence on quality performance for MMS is still a challenge. By considering the rate of incoming conforming product, manufacturing system quality transition between batch to batch, and quality propagation along stages, this paper investigates the appropriate batch policies and product sequencing for MMS so that satisfied quality performance can be achieved. A model to analyze the relationship between the product sequencing and quality performance is conducted just by using the quality inspection data and the complex engineering knowledge used in the variation method is avoided. Based on Markov Chain processes methodology, quality performance is modeled as a function of transition states jointly determined by multistage condition, product sequencing, incoming part quality, and propagation of the rate of conforming products among multistage. Quality related batch strategies are discussed for optimal quality performance. Two kinds of quality efficiency are put forward to facilitate the modeling and the discussion. The results of the model will lead to guidelines for quality management in multistage manufacturing systems

Optimization and analysis of cutting parameters using cryogenic media in machining of high strength alloy steel

In this research, liquid Argon is used as a cryogenic media to optimize the cutting parameters for evaluation of tool flank wear width of Tungsten Carbide Insert (CNMG 120404-WF 4215) while turning high strength alloy steel. Robust design concept of Taguchi L9 (34) method is applied to determine the optimum conditions. This analysis revealed is revealed that cryogenic impact is more significant in reduction of the tool flank wear

MANOVA with Summary Statistics: A STATA Program

Almost all available statistical packages are capable of performing Multivariate Analysis of Variance (MANOVA) from raw data. Some of statistical packages have capability to perform independent sample t-test, ANOVA and some other tests of significance on summary data, but you come across not single software that has the capability to perform MANOVA directly on summary data. A STATA programme has been written to perform Multivariate ANOVA on summary data. The programme computes available statistics for Multivariate ANOVA (i.e Willk’s Lembda, Lawley’s-Hotelling trace, Pillae’s trace and Roy’s largest root). The programme is also capable to perform Box–M test for testing equality of covariance matrices on summary data. Example has been given by using the programme on summary data to perform Multivariate ANOVA

Micro Propagation in Advanced Vegetable Production: A Review

Micro propagation is a fast method of plant propagation that has a great potential to develop high quality as well as disease-free plants. Advancements in this field have led to the development of several techniques for rapid multiplication and improvement of a wide range of horticultural crops and their production systems. Micro propagation includes three types of vegetative propagation, 1) somatic embryogenesis, 2) adventitious shoot production and 3) axillary shoot production, which provide excellent opportunities for successful vegetable crops production. In Capsicum genera, annuum-chinense-frutescens complex have been made with white flowers and small yellow seeds. A number of experiments have also been done to demonstrate the influence of hypocotyl explant orientation on shoot bud induction in Capsicum spp.  Sweet potato cuttings when grown in vitro with Florialite gives greater percentage of survival. Similarly, in vitro layering of gourds; a modification in micro propagation methods become more advantageous as it produces single shoot rather than multiple shoots. Likewise, an immobilized culture system of obtaining torpedo-stage embryos of carrots of uniform size and higher tuber yield with rapid multiplication rate for potato were also introduced by micro propagation techniques.

A Systematic Approach to Quality Oriented Product Sequencing for Multistage Manufacturing Systems

Product sequencing is one way to reduce cost and improve product quality for multistage manufacturing systems (MMS). However, systematically evaluating the influence of product sequence on quality performance for MMS is still a challenge. By considering the rate of incoming conforming product, manufacturing system quality transition between batch to batch, and quality propagation along stages, this paper investigates the appropriate batch policies and product sequencing for MMS so that satisfied quality performance can be achieved. A model to analyze the relationship between the product sequencing and quality performance is conducted just by using the quality inspection data and the complex engineering knowledge used in the variation method is avoided. Based on Markov Chain processes methodology, quality performance is modeled as a function of transition states jointly determined by multistage condition, product sequencing, incoming part quality, and propagation of the rate of conforming products among multistage. Quality related batch strategies are discussed for optimal quality performance. Two kinds of quality efficiency are put forward to facilitate the modeling and the discussion. The results of the model will lead to guidelines for quality management in multistage manufacturing systems

HYPOFRACTIONATED RADIOTHERAPY IN GLIOBLASTOMA MULTIFORME

Purpose: The purpose of this study was to assess the outcomes in glioblastoma patients treated with hypofractionated radiotherapy.Materials and Methods: We reviewed all glioblastoma patients treated at our specialist cancer centre over 7 and a 1⁄2 years using hypofractionated radiotherapy (HRT) postoperatively. The HRT regimen was 48 Gy given at 3 Gy/ fractions in 16 fractions. We calculated overall survival using time to event analyses. Results: A total of 62 patients were identi ed of whom 44 (71%) were male. The median age of these patients was 50 years (range: 20–71 years). Eastern Cooperative Oncology Group (ECOG) performance status was 0 in 47 (76%) and 1 in 15 (24%) patients. 7 (11%) of the patients underwent gross total resection, 52 (83%) had subtotal resection and 3 (5%) had a biopsy only. Response assessment on magnetic resonance imaging at 3-month post-HRT showed that 14 (22%) patients had regression, 21 (34%) were stable and 22 (35%) had a progressive primary tumour. 5 (8%) patients were lost to follow up. With a median follow-up of 7.8 months, the median overall survival was 9 months. Patients with ECOG-0 showed a median survival of 7 months as compared to 6 months for those with ECOG-1. Patients with stable or partial response showed a median overall survival of 8 months in comparison to 6 months for those with progressive disease. There were no signi cant differences in median survival based on the extent of surgery. A Cox multivariate model con rmed signi cant correlation of age and response to radiotherapy with survival. Conclusion: HRT consisting of 48 Gy in 3 weeks can be used for selected glioblastoma patients to reduce the overall treatment time of conventional radiotherapy by 35–40% without apparent increased toxicity or decrement in survival in a low resource environment. Key words: Chemoradiation, glioblastoma, hypofractionated radiotherapy, survival

Design, Synthesis, and Characterization of Poly(trimethylsilylmethyl methaciylate-co-chloromethyl styrene) for 193 nm Exposure

Requirements of materials for lithography at 193 am limit single layer resist candidates to those with high optical transmission. A random copolymer of trimethylsilymethyl methacrylate (SI) and chloromethyl styrene (CMS), [P(SI-CMS)], has been shown to be highly sensitive negative 193 nm resist in both bi-layer and single layer modes. Such resists show maximum sensitivity with an optical absorbance of the coating oflog10e, or 0.434. Through control of the mole ratio of the monomers in the P(SI-CMS) copolymer, absorbance values have been optimized for film thicknesses of0.2 - 0.3 micrometers for 90: 10 SI:CMS, 0.35 - 0.45 m for 95:5 SI:CMS and 0.55 -0.65 pm for 98:2 SI:CMS. Optical absorbance ofthe CMS is at a maximum in the 190 to 205 nm range, allowing the copolymer to be tailored for a large degree of crosslinking at a relatively low CMS concentration. Spray development of these materials is performed with ethanol, followed by a two step methanol I isopropanol-water rinse. Sensitivities are on the order of 4 to 20 mj/cm^2 at M near 40 000 g/mol. Furthermore, these ratios have been found to produce optimum 02 etch resistance