Fabrication des dispositifs à semi-conducteurs

Résumé

thumb|upright=1.5|Évolution de la finesse de gravure des processeurs entre 1970 et 2017 La fabrication des dispositifs à semi-conducteur englobe les différentes opérations permettant l'élaboration de composants électroniques basés sur des matériaux semi-conducteurs. Entrent dans cette catégorie de composants à semi-conducteur, les composants discrets qui n'ont qu'une seule fonction comme les diodes et les transistors, et les circuits intégrés plus complexes, intégrant plusieurs composants, jusqu'à des milliards, dans le même boîtier. Les circuits intégrés les plus courants dans les objets de tous les jours sont les microprocesseurs, les microcontrôleurs et les puces de mémoire comme les mémoires flash ou les mémoires vives dynamiques. On peut également citer parmi les dispositifs semi-conducteurs les MEMS, réalisant en plus de fonctions électriques, des fonctions mécaniques et les MOEMS, ajoutant également des fonctions optiques. Ces dispositifs utilisent les procédés standards de mic

Source officielle

https://fr.wikipedia.org/wiki/Fabrication_des_dispositifs_%C3%A0_semi-conducteurs

À propos de ce résultat

Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.

Publications associées (100)

Publications associées

Chargement

Personnes associées (119)

Personnes associées

Chargement

Unités associées (50)

Unités associées

Chargement

Concepts associés (132)

Concepts associés

Chargement

Cours associés (54)

Cours associés

Chargement

Séances de cours associées (113)

Séances de cours associées

Chargement

Diamond on GaN integration for power semiconductor devices with efficient thermal management

Reza Soleiman Zadeh Ardebili

The international actions against global warming demands reductions in carbon emission and more efficient use of energy. Energy efficiency in the conversion and use of electricity, as an important form of energy in the modern life, has strong environmental and economical impacts. Power electronic devices determining roles in the overall system efficiency in many applications such as power converters and inverters. Gallium Nitride (GaN) devices have emerged as an superior alternative to the silicon devices and enabled unprecedented efficiencies. GaN-based high electron-mobility transistors (HEMTs) offer excellent characteristics such as high switching speed, low switching and conduction losses, small device size and high power density capabilities. However, such significant increases in the power density and the reduction of device size comes at the price of dramatic increases in the heat fluxes and appearance of hot spots in the device footprint that cannot be addressed using conventional methods. The integration of diamond and GaN has been highly pursued for thermal management purposes as well as combining their exceptional complementary properties for power electronics applications and novel semiconductor heterostructures. In this thesis, we discuss the key hindrances towards realisation of diamond on GaN substrates and devices, and we propose novel solutions for improving the feasibility of diamond-on-GaN integration for efficient thermal management of hot spots in GaN devices and development of diamond devices integrated with GaN devices in the same chip.The growth of diamond on GaN is challenging due to the high lattice and thermal expansion mismatches. The weak adhesion of diamond to GaN and high residual stresses after the deposition often result in the diamond film delamination or development of cracks, which prevents the subsequent device fabrication. In this thesis, a new seed dibbling method is presented for seeding and growing high-quality diamond films on cost-effective GaN-on-Si substrates, which result in significantly larger diamond grains and lower residual stresses (as low as 0.2 GPa) compared to conventional methods. Moreover, the excellent adhesion obtained by this method enabled a reliable polishing of the as-grown diamond films on GaN-on-Si without any delamination, resulting in smooth diamond-on-GaN substrates with sub-nanometer roughness. The high temperature hot spots in GaN devices are addressed by the near-junction heat spreaders using diamond films deposited on GaN. An analytical model for the heat spreading is presented to analyse the performance and optimize the heat spreaders, considering the geometry and thermal conductivity of the heat spreader and the substrate. Experimental demonstration of diamond heat spreaders on vertical GaN diodes together with the thermal characterization of their behaviour shows significant reduction of thermal spreading resistances, hot spot temperatures and temperature gradients from the device footprint, which highlights the impact of such heat spreaders for the thermal management of high power density GaN devices.The diamond films deposited on GaN were also used to demonstrate high-performance diamond transistors integrated on AlGaN/GaN-on-Si substrates with characteristics such as high breakdown voltage, high current density, and high on/off ratio, which opens many new possibilities for the development of power ICs with complementary logics, gate drivers and power

EPFL2021

Chargement

A Suspended microchannel resonator (SMR) is composed by a hollow resonant structure containing embedded microfluidic channel. This device allows to circumvent the viscous damping confining the fluid to the inside of the resonant beam. The goal of this project is to optimize the device developed in A. de Pastina’s PhD work. She created and fabricated a SMR containing a microfluidic channel with piezoelectric electrodes embedded. The final objective is to measure mechanical properties of cells, studying their mass and stiffness. The deviation of these mechanical properties is linked to some diseases, as for the cancer cells. The use of this device, monitoring the advancement of specific disease, could be an alternative to surgical techniques. It allows also to reduce the time and the cost of the results and to personalize the cure, avoiding the use of an invasive approach. This project focuses on the fabrication of the two components of this device: electrodes and channels. Each step of the fabrication will be explained motivating the choice of materials and equipment used. Several references to the prior fabrication will be done, to understand which progress will be realized.

2020

Chargement

Crystal phase engineering is an exciting pathway to enhance the properties of conventional semiconductors. Metastable SiGe presents a direct band gap well suited for optical devices whereas wurtzite (WZ) phosphide alloys enable efficient light emission in the green spectral range. Availability of these materials could profoundly impact electronics as well as solid-state lighting industries. However, their synthesis in high quality and beyond nanowire size constraints remained elusive, hampering both scientific and commercial exploitation. In this thesis, we develop new approaches for metastable film growth to enable a platform for robust material characterization and device fabrication. Metal-organic vapor phase epitaxy is used to grow pure WZ nanowires and fins. To obtain planar layers, we explore two extensions of this well-known technique. The first one is based on conformal epitaxy and enables the use of standard (001)-oriented substrates. In this way, we achieve the controlled concurrent epitaxy of stable and metastable InP. We further propose a variation of this approach by using a nanowire as seed. This establishes a clear route for the synthesis of a large range of materials as is exemplarily demonstrated for WZ GaAs films. For the second technique we explore a method to enforce epitaxial lateral overgrowth on (111)A-oriented substrates. This allows to deposit pure WZ InP layers on insulator exceeding areas of 100 µm2, the largest ever demonstrated. We conceive a nucleation-based model and argue on a fundamental size limitation of metastable film epitaxy. Further advancement of this process allows to directly grow metastable micro- and nanostructures, which are optically isolated from the substrate. The high quality and shape-control of these crystals enables room-temperature lasing in WZ InP microdisks. This thesis demonstrates the successful development of new concepts to synthesize metastable semiconductors with pure crystalline phase and dimensions tailored towards planar device fabrication. We expect our findings to significantly contribute to the realization of crystal phase engineered electronic and optoelectronic devices.

EPFL2020

Chargement

EPFL2020

Diamond on GaN integration for power semiconductor devices with efficient thermal management

Reza Soleiman Zadeh Ardebili

EPFL2021