(f) Center of Excellence for VLSI Technology

(f) Center of Excellence for VLSI Technology

10.6 Objectives

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  To Fabricate Semiconductor Devices
  
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  To provide environment for conducting advanced research in the field of semiconductor technology
  
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  To develop a good research team to conduct research in the field of state-of-the-art nanotechnology
  
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  To train & develop skilled manpower for supporting the future electronics industries in Bangladesh
  
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  To develop higher efficiency solar cells
  
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  To initiate research collaboration with home & foreign universities and industries
  
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  To help the Government to achieve the goal of developing and industrializing high technologies
  

10.6.1 Available Research Facilities

i) Clean room organization

ii) Plasma enhanced chemical vapor deposition furnace

iii) Rapid thermal processing furnace

iv) Low pressure chemical vapor deposition furnace

v) Reactive ion etcher

vi) 4 -Probe station and analyzer

vii) Mini coater system/thermal and e-beam evaporator

viii) Stylus profilometer

ix) Wafer Characterization

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  To provide irradiation service to private companies for commercial purpose
  
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  To provide irradiation service to research organizations for R & D purpose.
  
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  To expand cooperation with other scientific organizations, universities, private and public sectors through mutual exchange of educational programs, training, technical cooperation and expert services.
  
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  To continue innovative R & D works related to Chitosan, Polygeline, Hydrogen Fuel Cell, Jute Fiber Reinforced Polymer Composites, Biodegradable Packaging Materials, Textile Dye Effluent, Polymer and Dye-Sensitized Solar Cell.
  
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  To develop human resources in the field of nuclear science and technology.
  

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  Extraction and Pilot Scale production of chitosan from prawn shell waste: Suitable methodology has been developed.
  
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  Application of extracted chitosan and Na-Alginate for plant growth promoter: Samples are field trialed for various vegetables and crops and optimum ratio, concentration and process has been developed.
  
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  Development of advanced wound dressing material: Bio-adhesive hydrocolloid dressing materials has been developed and characterized. Trials have been done in both animal and human subjects. Sample showed very high potential to be used as accelerated wound healing material.
  
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  Organic solarcell: Organic solar cell has been developed using thin film technology and locally available natural dye. Some very promising natural dyes have been indentified and purified.
  
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  Textile waste treatment: Researches are ongoing to develop sustainable treatment techniques for both liquid and solid textile waste. Waste has been successfully detoxified and modified to form biofertilizer. Development of suitable method for reuse textile waste water is also ongoing.
  
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  Green composite material: Light weight, durable and low cost composite materials have been developed. One of the most promising composite is Jutin which is made from jute reinforced polyester composite. Jutin is already well accepted in the mass population in Bangladesh and several field trials have been already done.
  
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  Recycling of waste: Extensive researches are conduced to recycle and reuse of several wastes like polyethylene, PET bottle, jute waste (caddies) etc.
  

Irradiation service provided to private companies for commercial purpose giving assurance of complete sterilization of products or deliver dose as per company demand. The statistics of revenue earned by the institute through radiation sterilization of spices, medical products and pharmaceutical raw materials during the reporting period are given below:

This is an on-going IAEA Regional Cooperation Agreement (RCA) project of BAEC. The prime objective of this project is (i) to assess the status of groundwater, especially origin & recharge condition of water, groundwater age, mixing pattern, water dynamics and connectivity of different aquifer systems; and (ii) to establish the baseline data on pollutants and isotopes of surface and groundwater for better management of groundwater resources. Under the project 58 nos. groundwater and 10 nos. river water samples were collected from different upazilla areas of Sylhet district for hydrochemical and isotopic analyses. The pH, Eh, temperature, electrical conductivity (EC), dissolved oxygen (DO) and HCO₃^- values of the collected groundwater samples ranged from 5.40 − 7.32, +73 to -27.8 mV, 24.2 to 27.5°C, 70.8-726 µS/cm and 22-244 mg/L respectively. The river water physiochemical parameters pH, Eh, temperature, electrical conductivity (EC), dissolved oxygen (DO) and HCO₃^- values ranged from 5.40 – 7.10, +24.4 to +73 mV, 25 to 27°C, 72.8-104 µS/cm and 22-60 mg/L respectively. All the samples for isotopic analysis were sent to the Isotope Hydrology Lab, IAEA, Vienna, Austria.

Under IAEA-GNIP (Global Network on Isotopes in Precipitation) project, Isotope Hydrology Div. installed three rain–gauge stations in Sylhet , Savar and Barisal area in order to collect rainfall samples for isotopic and hydrochemical analyses. The main goal of this project is to construct Local Meteoric Water Line (LMWL) to characterize the recharge origin, replenishment rate, mixing process, interconnection between aquifers and evaporation as well as to predict the climatic changes.

This was a joint collaborative research & development program (R&D) between Isotope Hydrology Div and Department of Botany, Jahangirnagar University. This work started from January 2011 and Completed on December 2011. Three areas i,e, EPZ industrial area, Bongshai river of Savar industrial area and AERE lake were selected for the study. Surface water was collected from those areas for the measurement of different physical, chemical and bio-chemical parameters. Among the three study area, EPZ area and Bongshai river area are highly polluted due to industrial effluent and AERE Lake is comparatively less polluted area. From the six months results, it is found that pH values of area ranges from 6.55-8.01, EC value ranges from 180-330 µS/cm, BOD ranges between 10-160 mg/L, COD values from 10-150 mg/L and TOC values varies from 10-50 mg/L. The effluents have considerable negative effects on the water quality of the receiving water bodies and as such, they are rendered not good for human use. It is therefore recommended that the careless disposal of industrial wastes without pretreatment should be discouraged.

Assessment and control of radiation exposure to occupational workers and the public have been performed as follows under the ERM program: Different environmental samples such as surface soil, surface water, underground water, vegetables, fish, milk, meat, etc., collected from 8 predefined locations around 10 km radial distances of the research reactor of AERE, were suitably processed and analyzed for the detection and measurement of different natural and artificial radioanuclides using Gamma Spectrometric System. The analysis revealed that only naturally occurring radionuclides were present in the measured samples and no contamination with artificial radioelements was detected. Therefore, there was no effect on the environment due to the operation of the Research Reactor (RR) and other radiological installations in AERE. . The radioactivity level obtained in the analysis was compared with the standard data. Moreover, different environmental samples such as soil, pond water, tube well water, vegetables etc., collected and analyzed from within 10 km radial distances around Rooppur Nuclear Power Plant site for baseline data. A report has been submitted to the convener of the relevant Working Technical Committee.

About 57 kg of solid radioactive waste (used resin) has been collected from resin column of 3MW TRIGA Mark II Research Reactor (RR) and were safely stored at the interim storage room of the Central Radioactive Waste Processing and Storage Facility (CWPSF). Contaminated animal carcasses (140 nos.) generated from QC related work of Radioisotope Production Division (RIPD) have been treated with Calcium-Oxide and safely stored for further management.

1. 
   Calibration & Standardization of Radiation Measuring Equipment & Dosimetry:
   

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  Calibration & standardization of 104 radiation survey meters/pocket dosimeters and 100 TLDs of Atomic Energy Center, Dhaka were performed. 2 electrometers and 7 ionization chambers of different Medical College Hospital have also been calibrated and standardized.
  
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  Radiation Dosimetry of Radiotherapy Units: Output dose of radiotherapy (Teletherapy: ⁶⁰Co) units of Dhaka Medical College Hospital, Dhaka and National Institute of Cancer Research and Hospital, Mohakhali, Dhaka have been measured in accordance with standard IAEA Protocol TRS-398. Moreover, using the SSD Laboratory facilities, the radiation dose calibration of Linear Accelerators (LINACs) of Khwaza Yunus Ali Medical College & Hospital, Sirajgong have been performed.
  
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  One electrometer and three ionization chambers of Shahid Ziaur Rahman Medical College and Hospital, Bogra and one electrometer and four ionization chambers of National Institute of Cancer Research and Hospital, Mohakhali, Dhaka were calibrated and Standardized.
  

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   Quality Assurance Program:
   

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  Five sets (total no. 11) of TLD of IAEA/WHO were irradiated as a part of inter comparison program for protection level and therapy level dosimetry.
  

The following radiation protection services were provided during the reporting period:

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  Radiation protection service has been provided at Institute of Radiation and Polymer Technology (IRPT) during the retrieval of Co-60 source from the stuck position to shielded condition.
  
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  Radiation survey has been performed on the surface of the newly prepared shielding container (as per recommendation of HPRWMU) of disused ⁶⁰Co source of radiotherapy department at Mymensingh Medical College Hospital (MMCH), Mymensingh for the safe transport of the disused source from MMCH to CWPSF, INST, AERE, Savar, Dhaka.
  
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  Internal doses of occupational radiation workers of INST and ROMU have been assessed by Canberra Fastscan Whole Body Counting System.
  
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  Radiation monitoring and protection services have been provided during the replacement of old detector (boron-carbide) by an uncompensated Ion Chamber at Reactor Operation Maintenance Unit (ROMU), AERE, Savar, Dhaka.
  
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  Routine radiation monitoring works have been performed at RIPD, RNPD, ROMU and IRPT of AERE.
  

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  Investigation on Natural and Artificial Radioactivity in Environmental Samples around TRIGA Mark-II Research Reactor of Bangladesh has been completed.
  
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  Efficiency Calibration of Whole Body Counting (WBC) System at Secondary Standard Dosimetry Laboratory (SSDL) of AERE, Savar, Dhaka”, has been performed.
  

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  Exploration of uranium, thorium and other associated precious metals.
  
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  Provide borehole grophysical logging services to different organizations.
  
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  Determine the geochemical, mineralogical and petrographical properties in terms of their radioactivity and economic potentiality.
  
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  Locate and present different data related to nuclear mineral exploration using GIS and Remote sensing and providing digital mapping service.
  
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  Find out the contamination level of soil and water in land and coastal region by radionuclide and heavy metals due to geoenvironmental changes.
  

iv) Determination of heavy minerals and elemental concentration present in the Kuakata Beach area.

v) Determination of elemental concentration of soil and sediment sample of the Jamuna river sediment, industrial area of savar and coastal area of Cox’s Bazar region.

vi) Coal sample analyses for elemental and ash content.

i) A project Entitled “Geo-electrical Investigation of the aquifer characteristics to delineate aquifer boundaries and ground water potential in Khulna City Area.” has been successfully completed under Special Allocation from the Ministry of Science and Technology for the Financial Year 2012-2013 with approval of the BAEC.

ii) A project Entitled “Radioactivity and Radon Measurement in the Sediment and Groundwater of Southeastern Coastal Area of Bangladesh” has been successfully completed under Special Allocation from the Ministry of Science and Technology for the Financial Year 2012-2013 with approval of the BAEC.

14.5 Service and Income

Providing geophysical logging services to Falgu Sandhani Limited, Sigma Associates and RFL Construction, NMU earned Tk.4,20,000/- (Taka four lacs twenty thousand) only.

15. Nuclear and Radiation Chemistry DIVISION, AERE

15.1 Research and Development Work

15.1.1 Study on chromium absorption from aqueous solution using iminodiacetic acid adsorbent prepared from glycidyl methacrylate grafted polyethylene

Iminodiacetic acid adsorbent was applied to remove chromium from aqueous solution by batch technique. The parameters like concentration of chromium in solution, pH of solution and contact time of adsorbent were investigated. The adsorption of chromium depends on concentration of chromium in solution, pH of solution and contact time of adsorbent. The maximum value of chromium (~88 mg/g of adsorbent) was removed from 100 mg/L chromium solution at pH 1.73 with contact time 24 h.

Superwater absorbent hydrogel (SWA) was prepared from aqueous solution of carboxymethy-lcellulose (CMC)/acrylic acid (AAc) blends followed by neutralization with alkali using Co-60 γ-irradiation source at room temperature. Gel fraction of SWA increases with increased radiation dose and concentration of AAc in CMC/AAc blend and attains a maximum value at 5 kGy radiation dose. With increased radiation dose as well as AAc content in blend, water absorption capacity of SWA decreases. SWA enhances the water retention capacity of sand and soil. Biodegradation of SWA was also investigated and found that it was biodegradable.

Periodically analysis of Cooling Water of TRIGA MARK-II Research Reactor was carried out.

During this period three M.Sc. students completed their thesis from Shahjalal University of Science and Technology and Dhaka University under the supervision of scientists of NRCD.

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  Validation of production and quality control equipment.
  
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  Test production of cold kits e.g. MDP, DTPA, DMSA etc.
  
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  Quality control of produced kits which include bio-distribution to mice, toxicity test, test for pyrogenecity, sterility etc.
  
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  One of the IAEA TC Project, BGD/6/022, “Producing Therapeutic Radiopharmaceuticals” with five fellowships and three scientific visits is under implementation.
  
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  Minimizing the higher level of radiation exposure during I-131 bulk solution dispensing
  

During the period 2012-2013, Radioisotope Production Division (RIPD) of the Institute of Nuclear Science and Technology produced 14-19 Tc-99m chromatographic generators every week and supplied to the nuclear medicine centers of the country. Import of generator is completely substituted by local production. RIPD is now meeting the full demand of Tc-99m generator of the Center of Nuclear Medicine & Ultrasound (CNMU’s) under the umbrella of Bangladesh Atomic Energy Commission. During this year RIPD has also supplied Tc-99m generators to some private and government run nuclear medicine centers (United Hospital, Apollo Hospitals and Lab Aid, Dhaka), and National Institute of Cardiovascular Diseases (NICVD) and Combined Military Hospital (CMH). The Tc-99m generators produced at the cGMP compliant new facility are comparable with the best quality generator available in the global market. The Tc-99m obtained from these generators are used for the diagnostic studies of different organs and organ system in nuclear medicine. During this fiscal year the division produced 821 Tc-99m generators in 49 batches (average strength 10 GBq/ generator). The price of 821 Tc-99m generators, fixed by Bangladesh Atomic energy commission, is approximately Tk. 6,34,038,000 (Six crores thirty four lacs and thirty eight thousand) whereas the actual market price is much higher.

Dispensing of bulk I-31 is cost effective. RIPD imported and dispensed 1284.32 GBq bulk I-131 in 22 batches according to the need of the nuclear medicine centers. The price of this dispensed bulk I-131, fixed by Bangladesh Atomic energy commission, is approx. 1,12,68,000/- Tk. (One crore twelve lacs sixty eight thousands only).

Cold kits are radiopharmaceuticals which work as carrier for Tc-99m by making complexes with Tc-99m. Each kit is organ particular so it is easier to diagnosis different organ and organ system using kits. With collaboration of IAEA TC project BGD 2011 and national ADP project the establishment of a kit production facility has been completed. This ISO certified clean room and all necessary equipment are functioning properly and some batches of Tc-99m cold kits are produced. Important quality parameters of produced kits have been checked before human administration which include bio-distribution to mice, toxicity test, test for apyrogenecity, sterility etc.

The Reactor and Neutron Physics Division consists of three different research groups and is carrying out Research and Development activities in the following three areas.

(a) Neutron Scattering (NS)

(b) Neutron Activation Analysis (NAA)

(c) Neutron Radiography (NR)

17.1 Research and Development Work

(a) Neutron Scattering (NS)

17.1.1 Synthesis and determination of structural parameters of La doped dielectric materials (Ba_1-xLa_xTiO₃ (x=0.01, 0.03 and 0.05) by X-ray and neutron diffraction  techniques

Lanthanum (La) doped BaTiO₃ was synthesized by polyvinyl alcohol (pva) evaporation method. Three different concentration of La (1.0, 3.0 and 5.0 at.%) were used for doping. All the samples were sintered at 135⁰C in air. Both the X-ray and Neutron diffractions were done to characterize the samples. The data were analyzed by the computer code RIETAN 2000 using Rietveld technique. The X-ray diffraction patterns of the three samples confirmed single phased tetragonal perovskite structure. Space group of the samples was found to be p4mm. The lattice parameters ‘a’ and ‘c’ were calculated from Bragg peak position using REITAN 2000 code. In X-ray diffraction method the measured values of ‘a’ and ‘c’ for x = x=0.01, 0.03 and 0.05 are 4.004348Å, 4.003709Å 4.069734Å and 4.040664Å, 4.031691 Å 4.036706 Å respectively. Similarly in neutron diffraction method the values of ‘a’ and ‘c’ for x = x=0.01, 0.03 and 0.05 are 3.995711 Å, 3.973596 Å, 3.991013 Å and 4.013869 Å, 3.919801 Å 3.991356 Å respectively. The agreement between observed and the calculated data was excellent and well consistent.

The spinel compounds Zn_xMn_1-xFeCrO₄ with x=0.2, 0.4, 0.6 and 0.8 have been prepared by solid state sintering method. X-ray diffraction studies were performed for structural characterization. X-ray diffraction patterns taken at room temperature showed that a single phased crystalline structure was developed in all the spinel compounds. After proper indexing of the X-ray diffraction patterns it appeared that the well known spinel structure having cubic symmetry were formed in the compounds. The lattice parameters () of the individual compound were calculated from the X-ray diffraction patterns using Nelson-Riley extrapolation method. It was observed that the value of lattice parameter gradually decreases with increasing Zn-ion substitution in the system.

Irradiation induced microstructural damage and nano hardness of the industrial grade stainless steel (SUS-316) have been studied under proton (H⁺) implanted condition at room temperature. The implantation scheme such as - proton flux (fluence), irradiation time, and penetration depth in the target materials were estimated by Monte Carlo Simulation Code SRIM-2008. X-ray diffraction study of the annealed samples prior to the proton implantation showed the austenitic fcc structure and no significant change was observed after proton implantation in it. Microstructural observation made by Scanning Transmission Electron Microscopy (STEM) revealed that 1 dpa of proton-irradiation induced the structural damage extended up to 1 µm depth from the surface. The nano hardness study showed that the hardness level of the irradiated sample increased monotonically with the irradiation doses. Proton dose of 1 dpa caused 65% increment of hardness level on average in case of uniformly irradiated samples. It was realized that the increment of hardness was a consequence of microstructural damages by the formation of interstitial dislocation loops in the sample matrix keeping the lattice structure unaffected.

A metallurgical study was carried out on a number of metallic samples collected from very old and abandoned forges situated near Izumo city of Shimane prefecture in Japan. Samples were designated as Kakehi Tatara (in Japanese) and identified as Kakehi-14, Kakehi-29, Kakehi-30, Kakehi-33, Kakehi-34 and Kakehi-35, as per the number of wells dug for hunting the samples. In the naked eye observation samples were looked like rusted iron lump of heterogeneous sizes having brownish and blackish colours. A variety of minerals such as- Wustite (FeO), Fayalite (2FeO.SiO₂), Hercinite (FeO.Al₂O₃), rutile (TiO₂), ulvospinel (2FeO.TiO₂) etc. were identified by observing the structural morphologies in optical microscopic studies. SEM-EDS (Scanning Electron Microscope equipped with Energy Dispersive X-ray Spectroscopy) study agreed with optical microscopic study and revealed that most of the samples were the composite of iron oxides along with a few amount of carbon, silica (SiO₂), alumina (Al₂O₃) etc. Vickers micro hardness test revealed that several samples were moderately hard and some others were nonmetallic oxides and too brittle to measure the hardness. It was concluded that the samples were the by-products of old blacksmith’s forges which were abandoned for hundreds of years.

The spinel system MgCr_xFe_2-xO₄ (x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) has been prepared by solid state sintering method in air at 1573K. X-ray and neutron powder diffraction experiments have been performed on the samples at room temperature for structural characterization. Rietveld refinement of the neutron diffraction data reveals that all the samples of the series possess cubic symmetry corresponding to the space group Fd3m. The distribution of the three cations Mg, Fe and Cr over the two sub lattices and other crystallographic parameters has been determined precisely. The results reveal that Cr has been substituted for Fe selectively. Cr ions invariably occupy the octahedral (B) site for all values of x. Mg and Fe ions are distributed over both A and B sites for all x values. With increasing ‘x’ the occupation of Mg increases in the A site and decreases in the B site for all the samples, while the Fe ions gradually decreases in both the sites for all values of ‘x’. The lattice constant decreases with increasing Cr content in the system. The magnetic structure at room temperature was ferrimagnetic for all the samples.