Mask design, fabrication and test NMOS transistor

Dalam proses fabrikasi MOSFET, satu set topeng digunakan bagi tujuan menutup atau membuka sesuatu kawasan pada silicon wafer. Set top eng yang digunakan dalam fabrikasi piawai adaIah sangat tinggi kosnya dan tidak praktikaI untuk tujuan pendidikan. Satu set top eng yang ekonomik adalah penyelesaiannya dengan menggunakan filem transparency yang mempunyai panjang saluran daripada 250um bingga maksimum 20um telah dihasilkan. Sebanyak 4 empat top eng telah direkabentuk dalam perisian AutoCAD 2002 drawing tools dan telah dicetak ke atas filem transparency. Kaedah contact printing digunakan untuk memindahkan bentangan topeng ke atas silicon waftr 4 inci menggunakan teknik standard photolithography untuk memastikan keseragamanlapisan. Proses fabrikasi MOSFET dilakukan selepas kesemua parameter dioptimumkan.Selepas MOSFET selesai dihasilkan, probe station dan MOSFET characterization analyzer software digunakan untuk menganalisa ciri-ciri MOSFET. Set topeng yang digunakan daIam projek ini adalah praktikal untuk tujuan pendidikan dan MOSFET yang dihasilkan juga berfungsi seperti yang dikehendaki

Cost effective mask design in CMOS transistor fabrication for undergraduates program

This paper presents a new innovative way of teaching undergraduate program using low cost masks. In MOSFET fabrication, the cost to produce a complete mask set for pattern transfer process extremely high and not cost effective for undergraduates program. The purpose of these masks is to define certain functional region on a wafer. In this work, low cost masks have been fabricated with a simple technology. An economical solution of masks using transparency films with various channel lengths from 300 µm to 500 µm has been produced. Six layer photolithography masks of MOSFET were designed using AutoCAD drawing tools and then printed using high resolution laser printer on the transparency film. Contact printing method has been utilized to transfer the mask layouts onto a 4-inch silicon wafer using standard photolithography techniques to check the line uniformity. Optical observation using high power microscope shows that the mask layouts were successfully transferred onto photoresist with minimum variation. These masks are used to fabricate an n-well CMOS transistor and then tested using Keithley 2400 source meter with Lab-view measurement software. The cost effective mask design proposed was really practical for teaching microfabrication undergraduates program

The effect of deposition time on the properties of titanium dioxide thin film prepared using CVD

This research aimed to investigate effect of deposition time on the structural, morphological properties and optical properties of the titanium dioxide (TiO2) thin film prepared using Chemical Vapour Deposition (CVD). This research involved two processes which are samples preparation process and characterisation process to fulfil the aim. The samples preparation process was done by synthesising TiO2 on indium thin oxide (ITO) substrates heated at 60 ̊C substrate temperature. Titanium butoxide used as the precursor for this chemical reaction was volatilised at 210 ̊C. Oxygen gas was flown at 1 litre per minute as the carrier gas. In order to study the effect of deposition time, the synthesise of the thin films were varied to 15, 30, 45 and 60 minutes. After synthesising process, the samples underwent thermal treatment via annealing process for 1 hour at 500 ̊C. For the characterisation process, Raman Spectroscopy technique was employed to investigate the structural properties of the samples. Apart from that, Field Emission Microscopy (FEM) technique, which was performed via FE-SEM, was employed to investigate the morphologies of the samples. Other than that, UV-Vis spectrometry was employed to analyse the optical properties of the samples. Analysis of data from Raman spectroscopy displayed four Raman Shifts for each sample which confirms that the samples exhibit TiO2 of anatase phases. Whereas, images from FE-SEM displayed reduction of nanoparticle clusters on the samples as the rate of deposition time increases. Meanwhile, UV-Vis analysis displayed transmittance of the samples ranging between 50% to 80% transmittance and each sample exhibits the same optical band gap at 3.25 eV

Gold nanoplates for a localized surface plasmon resonance-based boric acid sensor

Localized surface plasmon resonance (LSPR) properties of metallic nanostructures, such as gold, are very sensitive to the dielectric environment of the material, which can simply be adjusted by changing its shape and size through modification of the synthesizing process. Thus, these unique properties are very promising, particularly for the detection of various types of chemicals, for example boric acid which is a non-permitted preservative employed in food preparations. For the sensing material, gold (Au) nanoplates with a variety of shapes, i.e., triangular, hexagonal, truncated pentagon and flat rod, were prepared using a seed-mediated growth method. The yield of Au nanoplates was estimated to be ca. 63% over all areas of the sensing material. The nanoplates produced two absorption bands, i.e., the transverse surface plasmon resonance (t-SPR) and the longitudinal surface plasmon resonance (l-SPR) at 545 nm and 710 nm, respectively. In the sensing study, these two bands were used to examine the response of gold nanoplates to the presence of boric acid in an aqueous environment. In a typical process, when the sample is immersed into an aqueous solution containing boric acid, these two bands may change their intensity and peak centers as a result of the interaction between the boric acid and the gold nanoplates. The changes in the intensities and peak positions of t-SPR and l-SPR linearly correlated with the change in the boric acid concentration in the solution

Electrical resistivity and induced polarization techniques for groundwater exploration

Abstract: Electrical resistivity and induced polarization surveys have been conducted for groundwater exploration at two different sites of geological aged i.e. Carboniferous and Quaternary. This study discussed the earth materials resistivity and chargeability for metasedimentary rock and unconsolidated sediment for groundwater exploration at Kampung Jongok Batu, Dungun and Kampung Paya Rawa, Besut, respectively. For this study Terrameter LS2, cable, electrode, cable connector, battery and remote cable are tools for measurement. The spacing between electrodes is 5 m, maximum length of spread line is 400 m and using Pole-Dipole protocol. Via comparing between the resistivity and chargeability values able to provide better interpretation for ground water exploration for metasedimentary rock and unconsolidated quaternary sediment. The result shows the important of chargeability for refining the resistivity value for locating the groundwater position.Â

Fabrication and characterization of crystalline cupric oxide (CUO) films by simple immersion technique

Cupric oxide (CuO) is one of the most promising p-type semiconducting materials used in p-n junction solar cells. Most of the researchers use electrochemical deposition (ECD) to deposit CuO film. However, it always requires a conductive substrate and the resulting film is porous. In this work, we demonstrated a simple method using an immersion technique to deposit nanostructured CuO for p-n solar cell application. Compared to ECD which end up with only pyramid-like structure, an immersion technique offers flexibility on the CuO nanostructures such as spheres, particles, diamond etc. This technique also offers higher deposition rate which allow deposition at thicker thickness. The adherence to the substrate can be manipulated depending on the pH of the solution. The resuling film was tested into a p-n solar cell using configuration of Au/ZnO/Cuo/ITO/glass. Although there is no efficiency obtained under the solar radiation, it shows a solar cell characteristic with open circuit voltage (Voc) of 1.5

Fabrication of w-AlN Thin Films using Tilted Sputter Target and Unrotated Substrate Holder

Aluminium nitride (AlN) thin film is deposited by RF magnetron sputtering using Al sputtering target at room temperature. The sputter source was tilted 45° and the substrate holder was unrotated. The deposited AlN films were in the thickness range between 200 to 280 nm. The structural, elemental composition, morphological and topological properties of AlN with different thickness has been investigated. XRD analysis results revealed that all the AlN films deposited crystallize in hexagonal wurtzite phase (w-AlN). The crystal orientation of AlN (002) plane start to appear when the thickness of the AlN film increases and the thickest AlN film has a highest peak intensity of (002) plane with smallest FWHM indicated a good crystal quality of c-axis structure. The chemical composition of AlN analyze using EDS shows that all the films have AlN composition nearest to the stoichiometric and have a rice-like morphology regardless of the film thickness. The AFM analysis revealed that the surface roughness of the AlN films is increases along with the grain size as the thickness of the AlN films increased

Annealing Treatment on Homogenous n-TiO2/ZnO Bilayer Thin Film Deposition as Window Layer for p-Cu2O-Based Heterostructure Thin Film

Metal oxide semiconductor material has great potential to act as window layer in p–n heterojunction solar cell thin film owing to low production cost and significant properties in photo-voltaic mechanism. In this work, n-TiO2/ZnO bilayer thin film was effectively constructed by means of sol-gel spin coating technique in an effort to diminish the electron-hole recombination rate from single-layered thin film. Annealing time is one of the important parameters in the fabrication process and was varied to study the impact of annealing treatment towards the thin film characteristics as window layer. It was found that the optimum parameter for the n-TiO2/ZnO bilayer was 500 °C with an annealing time of 2 h. High crystallinity of the n-(101)-TiO2/(002)-ZnO bilayer thin film was obtained, which consists of anatase and a hexagonal wurtzite structure, respectively. Orientation of (002)-ZnO is essential for deposition with the (111) Cu2O-absorbing layer due to a low different lattice mismatch between these two interfaces. The homogenous morphology of n-TiO2/ZnO bilayer was observed with a compact and dense layer. The improvement of transmittance has also been achieved in a range of 60%–80%, which indicated that the incident light can penetrate throughout the thin film directly. In addition, a p-Cu2O absorbing layer was successfully fabricated on top of n-TiO2/ZnO bilayer thin film to form a p-n junction in order to visualize significant electrical rectification properties. The existence of p-Cu2O was confirmed by a (111)-peak orientation and triangular shape in structural and morphological properties, respectively

Annealing Treatment on Homogenous n-TiO2/ZnO Bilayer Thin Film Deposition as Window Layer for p-Cu2O-Based Heterostructure Thin Film

Metal oxide semiconductor material has great potential to act as window layer in p–n heterojunction solar cell thin film owing to low production cost and significant properties in photo-voltaic mechanism. In this work, n-TiO2/ZnO bilayer thin film was effectively constructed by means of sol-gel spin coating technique in an effort to diminish the electron-hole recombination rate from single-layered thin film. Annealing time is one of the important parameters in the fabrication process and was varied to study the impact of annealing treatment towards the thin film characteristics as window layer. It was found that the optimum parameter for the n-TiO2/ZnO bilayer was 500 °C with an annealing time of 2 h. High crystallinity of the n-(101)-TiO2/(002)-ZnO bilayer thin film was obtained, which consists of anatase and a hexagonal wurtzite structure, respectively. Orientation of (002)-ZnO is essential for deposition with the (111) Cu2O-absorbing layer due to a low different lattice mismatch between these two interfaces. The homogenous morphology of n-TiO2/ZnO bilayer was observed with a compact and dense layer. The improvement of transmittance has also been achieved in a range of 60%–80%, which indicated that the incident light can penetrate throughout the thin film directly. In addition, a p-Cu2O absorbing layer was successfully fabricated on top of n-TiO2/ZnO bilayer thin film to form a p-n junction in order to visualize significant electrical rectification properties. The existence of p-Cu2O was confirmed by a (111)-peak orientation and triangular shape in structural and morphological properties, respectively