Adhesion Effects on the Recrystallization of Silicon Films

1984 ◽  
Vol 35 ◽  
Author(s):  
C. E. Bleil ◽  
J. R. Troxell

ABSTRACTLaser processing of thin films of amorphous or polycrystalline silicon on insulator substrates, such as the glass normally used for liquid crystal displays, frequently leads to film thickness variations which are unacceptable for device fabrication. Some thickness variations are caused by the high surface tension of molten silicon and the poor adhesion of the silicon to the substrate. Techniques to reduce this problem by increasing the adhesion of the film to silicon dioxide coated Corning 7059 glass substrates have been investigated. Two different approaches were used. First, silicon ions were implanted into the silicon-glass interface to increase the direct bonding of the silicon to the silicon dioxide. Second, layers of material known to exhibit better adhesion to both silicon and silicon dioxide were introduced between the silicon film and the glass substrate. Both techniques produced films which, after subsequent laser processing, showed significantly reduced thickness variations. These procedures make it possible to laser process thin films of silicon on Corning 7059 glass substrates under conditions which produce large grain polysilicon films without producing unacceptably large thickness variations or film cracking.

2004 ◽  
Author(s):  
Gennady M. Mikheev ◽  
Ruslan G. Zonov ◽  
Dmitry G. Kaluzhny

2013 ◽  
Vol 845 ◽  
pp. 392-397 ◽  
Author(s):  
T. Joseph Sahaya Anand ◽  
Nor Hamizah Mazlan

Transition metal chalcogenide molybdenum ditelluride (MoTe2) thin films have been electrosynthesized cathodically on indium tin oxide-coated (ITO) conducting glass substrates from ammonaical solution of H2MoO4 and TeO2. The electrode potential was varied while the bath temperature was maintained at 40±1 oC and deposition time of 30 minutes. Highly textured MoTe2 films with polycrystalline nature are observed by X-ray diffraction analysis. Compositional analysis by EDX gives their stoichiometric relationships. Scanning electron microscope (SEM) was used to study surface morphology and shows that the films are smooth, uniform and useful for device fabrication. The optical absorption spectra showed that the material has an indirect band-gap value of 1.91-2.04 eV with different electrode potential. Besides, the film exhibited p-type semiconductor behavior. Keywords: Molybdenum ditelluride; Thin films; Electrodepositon; Solar cell;


1989 ◽  
Vol 157 ◽  
Author(s):  
Paul W. Mertens ◽  
Herman E. Maes

ABSTRACTIn zone melting recrystallization (ZMR) of thin silicon films different mechanisms can lead to thickness variations of the obtained silicon film. In this paper we will concentrate on some of these phenomena. One is the large scale mass transport, which typically leads to a thinned region at the start of the ZMR process. Another one, which is to a certain extent related to the first one, is the typical ripple formation that occurs especially under conditions that are commonly referred to as “low thermal gradient” regime.


Author(s):  
C. O. Jung ◽  
S. J. Krause ◽  
S.R. Wilson

Silicon-on-insulator (SOI) structures have excellent potential for future use in radiation hardened and high speed integrated circuits. For device fabrication in SOI material a high quality superficial Si layer above a buried oxide layer is required. Recently, Celler et al. reported that post-implantation annealing of oxygen implanted SOI at very high temperatures would eliminate virtually all defects and precipiates in the superficial Si layer. In this work we are reporting on the effect of three different post implantation annealing cycles on the structure of oxygen implanted SOI samples which were implanted under the same conditions.


Author(s):  
Frances M. Ross ◽  
Peter C. Searson

Porous semiconductors represent a relatively new class of materials formed by the selective etching of a single or polycrystalline substrate. Although porous silicon has received considerable attention due to its novel optical properties1, porous layers can be formed in other semiconductors such as GaAs and GaP. These materials are characterised by very high surface area and by electrical, optical and chemical properties that may differ considerably from bulk. The properties depend on the pore morphology, which can be controlled by adjusting the processing conditions and the dopant concentration. A number of novel structures can be fabricated using selective etching. For example, self-supporting membranes can be made by growing pores through a wafer, films with modulated pore structure can be fabricated by varying the applied potential during growth, composite structures can be prepared by depositing a second phase into the pores and silicon-on-insulator structures can be formed by oxidising a buried porous layer. In all these applications the ability to grow nanostructures controllably is critical.


Author(s):  
N. Lewis ◽  
E. L. Hall ◽  
A. Mogro-Campero ◽  
R. P. Love

The formation of buried oxide structures in single crystal silicon by high-dose oxygen ion implantation has received considerable attention recently for applications in advanced electronic device fabrication. This process is performed in a vacuum, and under the proper implantation conditions results in a silicon-on-insulator (SOI) structure with a top single crystal silicon layer on an amorphous silicon dioxide layer. The top Si layer has the same orientation as the silicon substrate. The quality of the outermost portion of the Si top layer is important in device fabrication since it either can be used directly to build devices, or epitaxial Si may be grown on this layer. Therefore, careful characterization of the results of the ion implantation process is essential.


Author(s):  
N. David Theodore ◽  
Juergen Foerstner ◽  
Peter Fejes

As semiconductor device dimensions shrink and packing-densities rise, issues of parasitic capacitance and circuit speed become increasingly important. The use of thin-film silicon-on-insulator (TFSOI) substrates for device fabrication is being explored in order to increase switching speeds. One version of TFSOI being explored for device fabrication is SIMOX (Silicon-separation by Implanted OXygen).A buried oxide layer is created by highdose oxygen implantation into silicon wafers followed by annealing to cause coalescence of oxide regions into a continuous layer. A thin silicon layer remains above the buried oxide (~220 nm Si after additional thinning). Device structures can now be fabricated upon this thin silicon layer.Current fabrication of metal-oxidesemiconductor field-effect transistors (MOSFETs) requires formation of a polysilicon/oxide gate between source and drain regions. Contact to the source/drain and gate regions is typically made by use of TiSi2 layers followedby Al(Cu) metal lines. TiSi2 has a relatively low contact resistance and reduces the series resistance of both source/drain as well as gate regions


2015 ◽  
Vol 9 (3) ◽  
pp. 2461-2469
Author(s):  
S. R. Gosavi ◽  
K. B. Chaudhari

CdS thin films were deposited on glass substrates by using successive ionic layer adsorption and reaction (SILAR) method at room temperature. The effect of SILAR growth cycles on structural, morphological, optical and electrical properties of the films has been studied.  The thickness of the deposited film is measured by employing weight difference method. The X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) studies showed that all the films exhibit polycrystalline nature and are covered well with glass substrates. The values of average crystallite size were found to be 53 nm, 58 nm, 63 nm and 71 nm corresponding to the thin films deposited with 30, 40, 50 and 60 SILAR growth cycles respectively. From the UV–VIS spectra of the deposited thin films, it was seen that both the absorption properties and energy bandgap of the films changes with increasing number of SILAR growth cycles. A decrease of electrical resistivity has been observed with increasing SILAR growth cycle. 


2018 ◽  
Vol 5 (2) ◽  
pp. 16-18
Author(s):  
Chandar Shekar B ◽  
Ranjit Kumar R ◽  
Dinesh K.P.B ◽  
Sulana Sundar C ◽  
Sunnitha S ◽  
...  

Thin films of poly vinyl alcohol (PVA) were prepared on pre-cleaned glass substrates by Dip Coating Method. FTIR spectrum was used to identify the functional groups present in the prepared films. The vibrational peaks observed at 1260 cm-1 and 851 cm-1 are assigned to C–C stretching and CH rocking of PVA.The characteristic band appearing at 1432 cm-1 is assigned to C–H bend of CH2 of PVA. The thickness of the prepared thin films were measured by using an electronic thickness measuring instrument (Tesatronic-TTD20) and cross checked by gravimetric method. XRD spectra indicated the amorphous nature of the films.Surface morphology of the coated films was studied by scanning electron microscope (SEM). The surface revealed no pits and pin holes on the surface. The observed surface morphology indicated that these films could be used as dielectric layer in organic thin film transistors and as drug delivery system for wound healing.


2019 ◽  
Vol 15 (34) ◽  
pp. 1-14
Author(s):  
Bushra A. Hasan

Lead selenide PbSe thin films of different thicknesses (300, 500, and 700 nm) were deposited under vacuum using thermal evaporation method on glass substrates. X-ray diffraction measurements showed that increasing of thickness lead to well crystallize the prepared samples, such that the crystallite size increases while the dislocation density decreases with thickness increasing. A.C conductivity, dielectric constants, and loss tangent are studied as function to thickness, frequency (10kHz-10MHz) and temperatures (293K-493K). The conductivity measurements confirm confirmed that hopping is the mechanism responsible for the conduction process. Increasing of thickness decreases the thermal activation energy estimated from Arhinus equation is found to decrease with thickness increasing. The increase of thickness lead to reduce the polarizability α while the increasing of temperature lead to increase α.


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