12 research outputs found
Epitaxie sélective en phase vapeur aux organométalliques pour la modulation de la longueur d'onde de multipuits quantiques InGaN/GaN
This thesis reports on the selective area metalorganic vapor phase epitaxy of InGaN/GaN multi-quantum wells for self-emissive micro-displays. GaN-based LEDs have been recognized to be very attractive for this application, thanks to their properties which include high brightness and efficiency allowing low power consumption and good reliability.To date, one of the main challenges ahead for the micro-displays technology is the production of full color devices integrating RGB emitting pixels, with a pixel pitch below 10 ”m. This study aims to achieve wavelength modulation of InGaN/GaN multi-quantum wells using selective area growth (SAG). This technique consists in patterning the surface of a substrate with a dielectric amorphous mask. During growth, the gas species do not deposit on the mask, but migrate to the openings defined beforehand. InGaN wells with different thicknesses (from 1 to 9 nm) can be obtained during the same growth run, resulting in different emission wavelengths from various regions on the wafers.The study presented in this manuscript is based on the selective growth of nitride layers, their characterisation, and the numerical simulation of SAG effects based on vapor-phase diffusion and surface diffusion. In a first part, the selective growth of the binary compound GaN and the InGaN alloy is investigating as function of growth conditions.Secondly, the influence of growth parameters and mask geometry on the properties of InGaN/GaN multiquantum wells is studied. This leads to the demonstration of an extended modulation of the emission wavelength measured by photoluminescence, from 405 to 608 nm in growth area of 3 ”m and obtained in a single localised growth run at 805 °C, allowing the possibility of applying this technique to the manufacture of emissive micro-displays.Cette thĂšse est consacrĂ©e Ă lâĂ©pitaxie sĂ©lective en phase vapeur aux organomĂ©talliques de multipuits quantiques InGaN/GaN pour la fabrication de micro-Ă©crans Ă©missifs. Les LEDs InGaN/GaN sont un candidat idĂ©al pour cette application, notamment en raison de leur forte luminositĂ© et leur grande fiabilitĂ© qui permet un haut rendement avec une faible consommation.A ce jour, le grand dĂ©fi des Ă©crans Ă©missifs est la rĂ©alisation d'un dispositif intĂ©grant des pixels rouge, vert et bleu avec un pas infĂ©rieur Ă 10 ”m. Lâobjectif de cette thĂšse est de dĂ©velopper des structures Ă multipuits quantiques InGaN/GaN Ă©mettant Ă diffĂ©rentes longueurs dâonde en utilisant l'Ă©pitaxie sĂ©lective en phase vapeur aux organomĂ©talliques. Cette technique consiste Ă masquer partiellement la surface du substrat avec une couche de matĂ©riau amorphe. Lors de la croissance, les espĂšces en phase gazeuse ne se dĂ©posent pas sur le diĂ©lectrique et migrent vers les ouvertures dĂ©finies en amont dans le masque. Il est ainsi possible d'obtenir lors d'une mĂȘme croissance des puits InGaN prĂ©sentant des Ă©paisseurs diffĂ©rentes, et donc des Ă©missions de diffĂ©rentes couleurs.LâĂ©tude prĂ©sentĂ©e dans ce manuscrit s'articule autour de la croissance, la modĂ©lisation numĂ©rique basĂ©e sur la diffusion de particules en phase vapeur et en surface, et la caractĂ©risation des empilements Ă©pitaxiĂ©s sĂ©lectivement. Nous Ă©tudions en premier lieu le dĂ©pĂŽt du composĂ© binaire GaN et de lâalliage InGaN avec un masque diĂ©lectrique afin de dĂ©finir les conditions de croissances autorisant une bonne sĂ©lectivitĂ©.Dans un second temps, nous Ă©tudions la croissance localisĂ©e de multipuits quantiques InGaN/GaN, et en particulier lâinfluence des effets de la croissance sĂ©lective sur les propriĂ©tĂ©s des structures en fonction des paramĂštres de croissance et de la gĂ©omĂ©trie du masque utilisĂ©. Nous dĂ©montrons notamment une modulation Ă©tendue de la longueur dâonde dâĂ©mission mesurĂ©e par photoluminescence, de 405 Ă 608 nm dans des zones de recroissance de 3 ”m obtenue en une seule croissance localisĂ©e Ă 805 °C, permettant dâenvisager lâutilisation de cette technique dans la fabrication dâĂ©crans Ă©missifs
Epitaxie sélective en phase vapeur aux organométalliques pour la modulation de la longueur d'onde de multipuits quantiques InGaN/GaN
This thesis reports on the selective area metalorganic vapor phase epitaxy of InGaN/GaN multi-quantum wells for self-emissive micro-displays. GaN-based LEDs have been recognized to be very attractive for this application, thanks to their properties which include high brightness and efficiency allowing low power consumption and good reliability.To date, one of the main challenges ahead for the micro-displays technology is the production of full color devices integrating RGB emitting pixels, with a pixel pitch below 10 ”m. This study aims to achieve wavelength modulation of InGaN/GaN multi-quantum wells using selective area growth (SAG). This technique consists in patterning the surface of a substrate with a dielectric amorphous mask. During growth, the gas species do not deposit on the mask, but migrate to the openings defined beforehand. InGaN wells with different thicknesses (from 1 to 9 nm) can be obtained during the same growth run, resulting in different emission wavelengths from various regions on the wafers.The study presented in this manuscript is based on the selective growth of nitride layers, their characterisation, and the numerical simulation of SAG effects based on vapor-phase diffusion and surface diffusion. In a first part, the selective growth of the binary compound GaN and the InGaN alloy is investigating as function of growth conditions.Secondly, the influence of growth parameters and mask geometry on the properties of InGaN/GaN multiquantum wells is studied. This leads to the demonstration of an extended modulation of the emission wavelength measured by photoluminescence, from 405 to 608 nm in growth area of 3 ”m and obtained in a single localised growth run at 805 °C, allowing the possibility of applying this technique to the manufacture of emissive micro-displays.Cette thĂšse est consacrĂ©e Ă lâĂ©pitaxie sĂ©lective en phase vapeur aux organomĂ©talliques de multipuits quantiques InGaN/GaN pour la fabrication de micro-Ă©crans Ă©missifs. Les LEDs InGaN/GaN sont un candidat idĂ©al pour cette application, notamment en raison de leur forte luminositĂ© et leur grande fiabilitĂ© qui permet un haut rendement avec une faible consommation.A ce jour, le grand dĂ©fi des Ă©crans Ă©missifs est la rĂ©alisation d'un dispositif intĂ©grant des pixels rouge, vert et bleu avec un pas infĂ©rieur Ă 10 ”m. Lâobjectif de cette thĂšse est de dĂ©velopper des structures Ă multipuits quantiques InGaN/GaN Ă©mettant Ă diffĂ©rentes longueurs dâonde en utilisant l'Ă©pitaxie sĂ©lective en phase vapeur aux organomĂ©talliques. Cette technique consiste Ă masquer partiellement la surface du substrat avec une couche de matĂ©riau amorphe. Lors de la croissance, les espĂšces en phase gazeuse ne se dĂ©posent pas sur le diĂ©lectrique et migrent vers les ouvertures dĂ©finies en amont dans le masque. Il est ainsi possible d'obtenir lors d'une mĂȘme croissance des puits InGaN prĂ©sentant des Ă©paisseurs diffĂ©rentes, et donc des Ă©missions de diffĂ©rentes couleurs.LâĂ©tude prĂ©sentĂ©e dans ce manuscrit s'articule autour de la croissance, la modĂ©lisation numĂ©rique basĂ©e sur la diffusion de particules en phase vapeur et en surface, et la caractĂ©risation des empilements Ă©pitaxiĂ©s sĂ©lectivement. Nous Ă©tudions en premier lieu le dĂ©pĂŽt du composĂ© binaire GaN et de lâalliage InGaN avec un masque diĂ©lectrique afin de dĂ©finir les conditions de croissances autorisant une bonne sĂ©lectivitĂ©.Dans un second temps, nous Ă©tudions la croissance localisĂ©e de multipuits quantiques InGaN/GaN, et en particulier lâinfluence des effets de la croissance sĂ©lective sur les propriĂ©tĂ©s des structures en fonction des paramĂštres de croissance et de la gĂ©omĂ©trie du masque utilisĂ©. Nous dĂ©montrons notamment une modulation Ă©tendue de la longueur dâonde dâĂ©mission mesurĂ©e par photoluminescence, de 405 Ă 608 nm dans des zones de recroissance de 3 ”m obtenue en une seule croissance localisĂ©e Ă 805 °C, permettant dâenvisager lâutilisation de cette technique dans la fabrication dâĂ©crans Ă©missifs
Epitaxie sélective en phase vapeur aux organométalliques pour la modulation de la longueur d'onde de multipuits quantiques InGaN/GaN
This thesis reports on the selective area metalorganic vapor phase epitaxy of InGaN/GaN multi-quantum wells for self-emissive micro-displays. GaN-based LEDs have been recognized to be very attractive for this application, thanks to their properties which include high brightness and efficiency allowing low power consumption and good reliability.To date, one of the main challenges ahead for the micro-displays technology is the production of full color devices integrating RGB emitting pixels, with a pixel pitch below 10 ”m. This study aims to achieve wavelength modulation of InGaN/GaN multi-quantum wells using selective area growth (SAG). This technique consists in patterning the surface of a substrate with a dielectric amorphous mask. During growth, the gas species do not deposit on the mask, but migrate to the openings defined beforehand. InGaN wells with different thicknesses (from 1 to 9 nm) can be obtained during the same growth run, resulting in different emission wavelengths from various regions on the wafers.The study presented in this manuscript is based on the selective growth of nitride layers, their characterisation, and the numerical simulation of SAG effects based on vapor-phase diffusion and surface diffusion. In a first part, the selective growth of the binary compound GaN and the InGaN alloy is investigating as function of growth conditions.Secondly, the influence of growth parameters and mask geometry on the properties of InGaN/GaN multiquantum wells is studied. This leads to the demonstration of an extended modulation of the emission wavelength measured by photoluminescence, from 405 to 608 nm in growth area of 3 ”m and obtained in a single localised growth run at 805 °C, allowing the possibility of applying this technique to the manufacture of emissive micro-displays.Cette thĂšse est consacrĂ©e Ă lâĂ©pitaxie sĂ©lective en phase vapeur aux organomĂ©talliques de multipuits quantiques InGaN/GaN pour la fabrication de micro-Ă©crans Ă©missifs. Les LEDs InGaN/GaN sont un candidat idĂ©al pour cette application, notamment en raison de leur forte luminositĂ© et leur grande fiabilitĂ© qui permet un haut rendement avec une faible consommation.A ce jour, le grand dĂ©fi des Ă©crans Ă©missifs est la rĂ©alisation d'un dispositif intĂ©grant des pixels rouge, vert et bleu avec un pas infĂ©rieur Ă 10 ”m. Lâobjectif de cette thĂšse est de dĂ©velopper des structures Ă multipuits quantiques InGaN/GaN Ă©mettant Ă diffĂ©rentes longueurs dâonde en utilisant l'Ă©pitaxie sĂ©lective en phase vapeur aux organomĂ©talliques. Cette technique consiste Ă masquer partiellement la surface du substrat avec une couche de matĂ©riau amorphe. Lors de la croissance, les espĂšces en phase gazeuse ne se dĂ©posent pas sur le diĂ©lectrique et migrent vers les ouvertures dĂ©finies en amont dans le masque. Il est ainsi possible d'obtenir lors d'une mĂȘme croissance des puits InGaN prĂ©sentant des Ă©paisseurs diffĂ©rentes, et donc des Ă©missions de diffĂ©rentes couleurs.LâĂ©tude prĂ©sentĂ©e dans ce manuscrit s'articule autour de la croissance, la modĂ©lisation numĂ©rique basĂ©e sur la diffusion de particules en phase vapeur et en surface, et la caractĂ©risation des empilements Ă©pitaxiĂ©s sĂ©lectivement. Nous Ă©tudions en premier lieu le dĂ©pĂŽt du composĂ© binaire GaN et de lâalliage InGaN avec un masque diĂ©lectrique afin de dĂ©finir les conditions de croissances autorisant une bonne sĂ©lectivitĂ©.Dans un second temps, nous Ă©tudions la croissance localisĂ©e de multipuits quantiques InGaN/GaN, et en particulier lâinfluence des effets de la croissance sĂ©lective sur les propriĂ©tĂ©s des structures en fonction des paramĂštres de croissance et de la gĂ©omĂ©trie du masque utilisĂ©. Nous dĂ©montrons notamment une modulation Ă©tendue de la longueur dâonde dâĂ©mission mesurĂ©e par photoluminescence, de 405 Ă 608 nm dans des zones de recroissance de 3 ”m obtenue en une seule croissance localisĂ©e Ă 805 °C, permettant dâenvisager lâutilisation de cette technique dans la fabrication dâĂ©crans Ă©missifs
The structure of InAlGaN layers grown by metal organic vapour phase epitaxy : effects of threading dislocations and inversion domains from the GaN template
International audienc
The structure of InAlGaN layers grown by metal organic vapour phase epitaxy : effects of threading dislocations and inversion domains from the GaN template
International audienc
Impact of Gate Drain Spacing on Low-Frequency Noise Performance of In Situ SiN Passivated InAlGaN/GaN MIS-HEMTs
International audienceIn this paper we investigated the gateâdrain access region spacing (L GD) effect on electrical and noise performance of InAlGaN/GaN metalâ insulatorâsemiconductor high electron mobility transistors (MIS-HEMTs) using in situ SiN cap layer as gate insulator. Different L GD of InAlGaN/GaN MIS-HEMTs using sub-10 nm barrier layer are studied. Low-frequency noise measurements have been carried out for the first time in order to analyze the impact of the gateâdrain spacing on the electrical characteristics. The noise of the channel under the gate has been identified as the dominant channel noise source for L GD < 10 ÎŒm. Finally, the calculated Hooge parameter (α H) is equal to 3.1 Ă 10 â4. It reflects the high material quality while using sub-10 nm InAlGaN layer, which is promising for high-frequency applications
Cl<sub>2</sub>/Ar based atomic layer etching of AlGaN layers
International audienceThis paper reports on atomic layer etching of several III-N materials such as GaN, AlN, AlGaN, and InAlGaN based on a sequential surface modification by chlorine adsorption followed by a low energy Ar plasma exposure to remove the modified layer using a reactive ion etching system. A study on the influence of several parameters, such as gas flow rates, removal step duration, RIE power and number of cycles on the etch per cycle, and the root-mean-square roughness, is performed. Low etch per cycle from 0.17 to 1.85 nm/cycle, respectively, for AlGaN and GaN and surfaces as smooth as the as-grown samples were obtained. The developed process is intended to be used for normally off GaN-based high electron mobility transistor processing
InAlGaN/GaN HEMTs at Cryogenic Temperatures
We report on the electron transport properties of two-dimensional electron gas confined in a quaternary barrier InAlGaN/AlN/GaN heterostructure down to cryogenic temperatures for the first time. A state-of-the-art electron mobility of 7340 cm2·Vâ1·sâ1 combined with a sheet carrier density of 1.93 Ă 1013 cmâ2 leading to a remarkably low sheet resistance of 44 Ω/⥠are measured at 4 K. A strong improvement of Direct current (DC) and Radio frequency (RF) characteristics is observed at low temperatures. The excellent current and power gain cutoff frequencies (fT/fmax) of 65/180 GHz and 95/265 GHz at room temperature and 77 K, respectively, using a 0.12 ÎŒm technology confirmed the outstanding 2DEG properties