Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Open Access Guideline
Open Access Guideline
Postgraduate Thesis Guideline
Postgraduate Thesis Guideline
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
Design and fabrication of strained light emitting germanium microstructures by liquid phase epitaxy
Download
10421011.pdf
Date
2021-9
Author
Ünlü, Buse
Metadata
Show full item record
This work is licensed under a
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License
.
Item Usage Stats
279
views
154
downloads
Cite This
Germanium is compatible with CMOS technology and can be utilized for the development of an integrated laser on Si platforms. Nevertheless, it is a very inefficient light emitter owning to its indirect bandgap. On the other hand, the application of tensile strain reduces the split in between direct and indirect band edges of Ge, which in turn enhances its light emission efficiency, and converts it into a direct bandgap material. In this thesis, firstly finite element model simulations are performed to determine the dimensions of the most efficient Ge microstructures providing the highest possible biaxial and uniaxial strain levels. Following that, Ge microstructures are fabricated, in which silicon nitride acts as a stressor layer on top and sides. Radio frequency magnetron sputtering, a straightforward, low-cost, and environmentally friendly method, is used for both amorphous Ge and the stressor film deposition processes. The liquid phase epitaxy technique is utilized to crystallize the amorphous Ge. It is demonstrated that one single annealing step converts the Ge to a single crystal and induces tensile stress to the nitride film, simultaneously. Moreover, the proceeding wet chemical etching steps promote the tensile strain induction in the Ge microstructures. The amount of strain can easily be tuned by changing the type and duration of wet etching processes. A uniaxial strain level of up to 3.5% has been demonstrated by Raman and micro photoluminescence spectroscopy, and verified by FEM simulations. Results of this study pave the way to obtain infrared Ge lasers on Si chips by utilizing cost-efficient and easy-to-use deposition and crystallization techniques.
Subject Keywords
Germanium
,
Strain Introduction
,
Stressor Layer
,
LPE
,
Luminescence
URI
https://hdl.handle.net/11511/93094
Collections
Graduate School of Natural and Applied Sciences, Thesis
Suggestions
OpenMETU
Core
Development of a large area germanium on insulator platform by liquid phase epitaxy
Özyurt, Zişan İrem; Yerci, Selçuk; Department of Micro and Nanotechnology (2017)
Germanium is a group IV element compatible with CMOS (Complementary metal oxide semiconductor) fabrication technology and advantageous over silicon by having smaller band gap and higher carrier mobility, which provide infrared photodetectors and high-speed transistors respectively. In addition, by having direct band gap, strained-Ge enables fabrication of infrared lasers. Finally, thanks to lattice-matching, Ge layers on Si can also be used as virtual substrates for the growth of III-V compounds on Si. In o...
Design and implementation of a single slope adc for digital output cooled infrared readout integrated circuits
Akyürek, Fatih; Bayram, Barış; Department of Electrical and Electronics Engineering (2016)
Readout Integrated Circuits (ROIC) have been commonly implemented with analog video output buffers throughout history. Image signals are converted into digital by an external ADC card, which is placed outside the Dewar. Although analog output method is easier to implement, it is susceptible to the environmental noise due to the non-differential output. Moreover, the ADC proximity card placed outside of the dewar contributes to the system complexity. This thesis presents the design of a single slope ADC dedi...
Improvement of light emission from Tb-doped Si-based MOS-LED using excess Si in the oxide layer
Kulakci, Mustafa; Turan, Raşit (2013-05-01)
The fabrication of efficient silicon-based Light Emitting Devices (LEDs) is extremely important for the integration of photonic and electronic components on the same Si platform. In this paper, we report on the room temperature electroluminescence properties of Tb-doped MOS-LED devices with an active layer of SiO2 and Si-rich SiOx produced using the magnetron co-sputtering technique. The electroluminescence properties of both types of devices were studied as a function of processing conditions and material ...
Manufacturing of Functionally Graded Porous Products by Selective Laser Sintering
Erdal Erdoğmuş, Merve; Dağ, Serkan (2008-09-25)
Selective laser sintering (SLS) is a rapid prototyping technique which is used to manufacture plastic and metal models. The porosity of the final product obtained by SLS can be controlled by changing the energy density level used during the manufacturing process. The energy density level is itself dependent upon manufacturing parameters such as laser power, hatching distance and scanning speed. Through mechanical characterization techniques, it is possible to quantitatively relate the energy density levels ...
MODELING OF A CAPACITIVE Sigma-Delta MEMS ACCELEROMETER SYSTEM INCLUDING THE NOISE COMPONENTS AND VERIFICATION WITH TEST RESULTS
Boga, Biter; Ocak, Ilker Ender; Külah, Haluk; Akın, Tayfun (2009-01-29)
This paper presents a detailed SIMULINK model for a conventional capacitive Sigma-Delta accelerometer system consisting of a MEMS accelerometer, closed-loop readout electronics, and signal processing units (e. g. decimation filters). By using this model, it is possible to estimate the performance of the full system, including the effect of individual noise components, operation range, scale factor, etc. The model has been verified through test results using a lateral accelerometer, full-custom designed 2nd-...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
B. Ünlü, “Design and fabrication of strained light emitting germanium microstructures by liquid phase epitaxy,” M.S. - Master of Science, Middle East Technical University, 2021.