Buffer Layers for Ferroelectric-Based Infra-Red Detectors on Si Grown by a Novel CVD Method

1994 ◽  
Vol 299 ◽  
Author(s):  
Gregory T. Stauf ◽  
Peter C. VanBuskirk ◽  
Peter S. Kirlin ◽  
Walter P. Kosar

AbstractFerroelectrics such as PbTiO3 and BaSrTiO3 are promising candidates for pyroelectric infrared detector materials. Integration of ferroelectric thin films on Si will permit fabrication of low-cost infrared detector arrays, but a buffer layer will be required to reduce interactions with the substrate. For this reason we have investigated MOCVD of MgAl2O4 and yttria-stabilized zirconia (YSZ) buffer layers on both Si and MgO. A single source molecule, magnesium dialuminum isopropoxide (Mg[Al(OCH(CH3)2)4]2), was used for deposition of the MgAl2O4, the first time to our knowledge that well characterized multi-metal oxide films have been deposited by CVD from a single-source compound. Both EDAX and RBS showed film stoichiometries consistent with the elemental ratio in the source. A novel liquid solution-based flash vaporization technique was used to transport the organometallic sources into the reactor, providing both excellent reproducibility and ease of stoichiometry control and deposition rate. Highly oriented [100] MgAl2O4 was grown on MgO, and [100] YSZ was grown on MgO and Si. Degree of preferred orientation of the YSZ was found to be dependent on oxygen partial pressure, both for the MgO and Si substrates.

1995 ◽  
Vol 379 ◽  
Author(s):  
P. Müller ◽  
A.N. Tiwari ◽  
H. Zogg

Narrow gap IV-VI materials like PbS, PbSnSe and PbSnTe are used for infrared detector device fabrication [1,2]. Earlier an intermediate Ila-fluoride buffer layer, which consisted of a BaF2/CaF2-stack of about 2000 Å thickness, was used to get epitaxial high quality layers on silicon substrates. This buffer is now reduced to a much thinner layer of only about 20 Å thick CaF2, regardless the large lattice mismatch between layer and substrate [3,4,5]. The question therefore arises if high quality IV-VI layers can be grown on Si-substrates without any buffer layer as e.g. in CdTe/Si or GaAs/Si systems.The aim of this work is to grow IV-VI layers directly on Si-substrates without any buffer layers to study the growth kinetics and epitaxial quality. PbSe was chosen as a representant of IV-VI materials, and layers were grown on (111)- and (100)-oriented silicon substrates.


1986 ◽  
Vol 71 ◽  
Author(s):  
H. Zogg ◽  
W. Vogt ◽  
H. Melchior

AbstractComposition graded buffer layers of group Ila fluorides allow the heteroepitaxial growthof device quality narrow gap lead chalcogenides onto Si. Mechanical stresses in the layers are almost completely relaxed at room temperature despite large thermal expansion mismatches. Photovoltaic infrared sensors with up to about 9.5 um cut—off wavelengths and which operate at or near the 300K background noise limit have been fabricated in such PbTe and (Pb,Sn)Se on Si structures.Furthermore, epitaxial graded fluoride buffers seem to be suited to connect other semiconductors with even large lattice mismatches. Initial heteroepitaxial growth of CdTe on fluoride/Si(lll) substrates (mismatch 20%) supports such more general applications.


2000 ◽  
Vol 10 (01) ◽  
pp. 47-53
Author(s):  
G. J. BROWN ◽  
F. SZMULOWICZ ◽  
K. MAHALINGAM ◽  
A. SAXLER ◽  
R. LINVILLE ◽  
...  

New infrared (IR) detector materials with high sensitivity, multi-spectral capability, improved uniformity and lower manufacturing costs are required for numerous space-based infrared imaging applications. To meet these stringent requirements, new materials must be designed and grown using semiconductor heterostructures, such as quantum wells and superlattices, to tailor new optical and electrical properties unavailable in the current generation of materials. One of the most promising materials is a strained layer supperlattice (SLS) composed of thin InAs and GaInSb layers. While this material shows theoretical and early experimental promise, there are still several materials growth and processing issues to be addressed before this material can be transitioned to the next generation of infrared detector arrays. Our research is focused on addressing the basic materials design, growth, optical properties, and electronic transport issue of these superlattices.


2014 ◽  
Vol 2014 ◽  
pp. 1-4
Author(s):  
Kuen-Hsien Wu

This paper demonstrated the fabrication and optoelectronic characteristics of ZnO ultraviolet (UV) photodetectors fabricated on Si substrates with oxidized nano-porous-Si (ONPS) buffer layers. ONPS layers were prepared on the surfaces of Si substrates by use of an electrochemical anodization technique following a rapid-thermal-oxidation process. Experimental results indicated that application of ONPS buffer layers not only improved the crystallinty of the deposited ZnO thin films but also greatly restricted the visible-to-infrared photoresponse that was generated from the light absorption of Si substrates. The developed ZnO-on-ONPS photodiodes achieved high photoresponsivity for the incident UV light of 300 ∼ 400 nm and got a large photo-to-dark current ratio up to 104 at wavelength of 375 nm under a bias of 5 V. Therefore, ZnO on ONPS provides a highly potential approach for the development of low-cost visible-blind UV photodetectors.


2003 ◽  
Author(s):  
Selim Eminoglu ◽  
M. Y. Tanrikulu ◽  
Tayfun Akin

Sensor Review ◽  
2001 ◽  
Vol 21 (4) ◽  
pp. 283-287 ◽  
Author(s):  
Stephen Porter ◽  
Mike Mansi ◽  
Neil Sumpter ◽  
Lindsay Galloway

Author(s):  
K.M. Hones ◽  
P. Sheldon ◽  
B.G. Yacobi ◽  
A. Mason

There is increasing interest in growing epitaxial GaAs on Si substrates. Such a device structure would allow low-cost substrates to be used for high-efficiency cascade- junction solar cells. However, high-defect densities may result from the large lattice mismatch (∼4%) between the GaAs epilayer and the silicon substrate. These defects can act as nonradiative recombination centers that can degrade the optical and electrical properties of the epitaxially grown GaAs. For this reason, it is important to optimize epilayer growth conditions in order to minimize resulting dislocation densities. The purpose of this paper is to provide an indication of the quality of the epitaxially grown GaAs layers by using transmission electron microscopy (TEM) to examine dislocation type and density as a function of various growth conditions. In this study an intermediate Ge layer was used to avoid nucleation difficulties observed for GaAs growth directly on Si substrates. GaAs/Ge epilayers were grown by molecular beam epitaxy (MBE) on Si substrates in a manner similar to that described previously.


2014 ◽  
Vol 881-883 ◽  
pp. 1117-1121 ◽  
Author(s):  
Xiang Min Zhao

ZnO thin films with different thickness (the sputtering time of AlN buffer layers was 0 min, 30 min,60 min, and 90 min, respectively) were prepared on Si substrates using radio frequency (RF) magnetron sputtering system.X-ray diffraction (XRD), atomic force microscope (AFM), Hall measurements setup (Hall) were used to analyze the structure, morphology and electrical properties of ZnO films.The results show that growth are still preferred (002) orientation of ZnO thin films with different sputtering time of AlN buffer layer,and for the better growth of ZnO films, the optimal sputtering time is 60 min.


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