000203826 001__ 203826
000203826 005__ 20190509132516.0
000203826 0247_ $$2doi$$a10.5075/epfl-thesis-6451
000203826 02470 $$2urn$$aurn:nbn:ch:bel-epfl-thesis6451-7
000203826 02471 $$2nebis$$a10335518
000203826 037__ $$aTHESIS 000203826 041__$$aeng
000203826 088__ $$a6451 000203826 245__$$bModeling, Design, and Characterization$$aUltra-Low-Temperature Silicon and Germanium-on-Silicon Avalanche Photodiodes 000203826 269__$$a2014
000203826 260__ $$bEPFL$$c2014$$aLausanne 000203826 336__$$aTheses
000203826 502__ $$aProf. J.-Ph. Thiran (président) ; Prof. E. Charbon (directeur) ; Prof. E. Cantatore, Prof. G. De Micheli, Prof. L.K. Nanver (rapporteurs) 000203826 520__$$aIn this thesis we propose the use of photodiodes fabricated in planar technologies to address the detection problem in these applications. A number of solutions exist, optimized for these wavelengths, based on Germanium (Ge) and other III-V materials. In this thesis we focused on Ge thanks to its versatility and ease to use in the clean room. The main advantage of this material is in fact a good compatibility with Silicon and standard CMOS processes. Note that the proposed technology is not based on Silicon/Germanium (SiGe), whereby Ge is used to strain Si to achieve higher bandwidth in Si, not higher sensitivity. In our pure Ge approach, Ge is grafted onto Si (Ge-on-Si), achieving high responsivity at wavelengths of 900nm and higher. The proposed devices can operate in avalanche mode (avalanche photodiodes - APDs), and in Geiger mode (Geiger mode APDs (GAPDs) or single-photon avalanche diodes (SPADs)). To combine the advantages of Ge with single-photon sensitivity and excellent timing resolution of Si-based SPADs, this thesis proposes a new generation of SPADs, achieved in collaboration with Prof. Nanver at TUDelft, aimed at near-infrared range. The fabrication process of the Ge-on-Si SPAD approach, which we are investigating together with the TUDelft group, consists of a standard CMOS process combined with post-processing steps to grow Ge on top of a Si/SiO2 layer. In our study we have investigated the potential for a new generation of massively parallel, Ge-on-Si sensors fabricated in fully CMOS compatible technology. The objective was to address the next challenges of super-parallel pixel arrays, while exploiting the advantages of Ge substrate. The key technology developed in the thesis is a selective chemical-vapor deposition (CVD) epitaxial growth. A novel processing procedure was developed for the p+ Ge surface doping by a sequence of pure-Ga and pure-B depositions (PureGaB). The resulting p+n diodes have exceptionally good I-V characteristics with ideality factor of ~1.1 and low saturation currents. They can be operated both in proportional and in Geiger mode, and exhibit relatively low dark counts. We also looked at techniques to improve red and infrared sensitivity in conventional deep-submicron CMOS processes, by careful selection of standard layers at high depths in the Si substrate. Using the proposed approach, 12 µm-diameter SPADs were fabricated in 0.18µm CMOS technology showing low dark count rates (363 cps) at room temperature and considerably lower rates at cryogenic temperatures (77 K), while the FWHM timing jitter is as low as 76 ps. That of cryogenic SPADs is a novel research direction and in this thesis it was advocated as a significant trend for the future of optical sensing, especially in mid-infrared wavelengths. Low temperature characterizations reported in this thesis exposed how the relevant properties of fabrication materials, such as strength, thermal conductivity, ductility, and electrical resistance are changing. One of the most important properties is superconductivity in materials cooled to extreme temperatures: this is an important trend that will be pursued in the future activities of our group.
000203826 6531_ $$aAvalanche Photodiode 000203826 6531_$$aAPD
000203826 6531_ $$aCryogenic 000203826 6531_$$aCMOS compatible
000203826 6531_ $$aGermanium 000203826 6531_$$aGe-on-Si
000203826 6531_ $$aNear-Infrared 000203826 6531_$$aSingle photon avalanche diode
000203826 6531_ $$aSPAD 000203826 6531_$$aSPAD array
000203826 700__ $$0243383$$g192052$$aAminian, Mahdi 000203826 720_2$$aCharbon, Edoardo$$edir.$$g146991$$0240305 000203826 8564_$$uhttps://infoscience.epfl.ch/record/203826/files/EPFL_TH6451.pdf$$zn/a$$s23192822$$yn/a 000203826 909C0$$xU12178$$0252106$$pAQUA
000203826 909CO $$pthesis$$pthesis-bn2018$$pDOI$$ooai:infoscience.tind.io:203826$$qDOI2$$qGLOBAL_SET$$pSTI 000203826 917Z8$$x108898
000203826 917Z8 $$x108898 000203826 917Z8$$x108898
000203826 917Z8 $$x108898 000203826 917Z8$$x108898
000203826 918__ $$dEDEE$$cIEL$$aSTI 000203826 919__$$aGR-SCI-IC
000203826 920__ $$b2014$$a2014-12-22
000203826 970__ $$a6451/THESES 000203826 973__$$sPUBLISHED$$aEPFL 000203826 980__$$aTHESIS