L. Gerbaud

Bio: L. Gerbaud is an academic researcher from Grenoble Institute of Technology. The author has contributed to research in topics: Power semiconductor device & Die (integrated circuit). The author has an hindex of 2, co-authored 2 publications receiving 5 citations.

Optimization of a power mosfet and its monolithically integrated self-powering circuits

Abstract: The paper presents a physical structure optimizat ion of an integrated semiconductor device design: a power MOSFET and other vertical transistors are integrated within the same die, introducing a novel self supplied power transistor This integrat ed optimal design leads to complex optimization problems with close constraints The main constrain t deals with the avalanche phenomenon that is formulated by multiple integral expressions of nume rical functions The paper focuses on two aspects: the integral formulation of the avalanche model and mor e specifically its gradient computation in the view of applying a gradient-based optimization algorithm, a nd the comparisons of several optimization methods on this problem Keywords : Genetic optimization algorithms, gradient-based o ptimization algorithm, integration constraint, Power MOSFETs, design of monolithically integrated circuits

Towards reduced threshold voltages for vertical power Mosfet transistors

Abstract: The threshold voltage of insulated gate power transistors usually is around 3 to 4V and their nominal gate to source voltage between 15 and 20V. These unanimously recognized electrical characteristics are questioned in this paper in order to evaluate which benefits could be drawn from a reduction of the threshold voltage of power transistors. Logic level MOSFETs already exist, but this paper chooses to study theoretically the electrical and physical characteristics of power transistors as a function of the threshold voltage to see if these electrical values of power electronics standards are still appropriate. It appears that the reduction of the threshold voltage of power MOSFET reduces the amount of control power and may improve switching characteristics.

Méthodes et modèles pour une approche de dimensionnement géométrique et technologique d'un semi-conducteur de puissance intégré. Application à la conception d'un MOFSET vertical

Abstract: Dans cette these, nous abordons la conception des composants d'electronique de puissance, integres sur semi-conducteur. Dans cette large problematique, nous nous interessons plus particulierement aux methodes et outils logiciels et numeriques pour le dimensionnement technologique et geometrique. Ainsi, nous abordons le dimensionnement en faisant des compromis d'integration entre la technologie du composant de puissance et les fonctions electriques de ses composants annexes, en prenant en compte la fiabilite de la realisation technologique en salle blanche et les impacts de l'environnement electronique. Pour cela, nous avons propose des demarches, methodes et outils pour repousser les limites existantes de la conception, visant a offrir le support correspondant en terme de « design kit ». Finalement, nous appliquons les methodes et les demarches choisies et developpees, au dimensionnement d'un MOSFET de puissance (VDMOS), pour differents cahiers des charges.

Electric field distribution and voltage breakdown modeling for any PN junction

Abstract: Purpose – Scientists and engineers have been solving Poisson’s equation in PN junctions following two approaches: analytical solving or numerical methods. Although several efforts have been accomplished to offer accurate and fast analyses of the electric field distribution as a function of voltage bias and doping profiles, so far none achieved an analytic or semi-analytic solution to describe neither a double diffused PN junction nor a general case for any doping profile. The paper aims to discuss these issues. Design/methodology/approach – In this work, a double Gaussian doping distribution is first considered. However, such a doping profile leads to an implicit problem where Poisson’s equation cannot be solved analytically. A method is introduced and successfully applied, and compared to a finite element analysis. The approach is then generalized, where any doping profile can be considered. 2D and 3D extensions are also presented, when symmetries occur for the doping profile. Findings – These results an...

Conception et hybridation de l'environnement électronique des composants de puissance à structure verticale

Abstract: Ces travaux de these portent sur l'integration heterogene des fonctions de commande pour des transistors de puissance verticaux a grille isolee. Ce travail a consiste en la conception des fonctions de commande pour un transistor de type MOSFET en technologie CMOS planar, puis en la conception du composant de puissance lui-meme, incluant des fonctions specifiques pour l'auto-alimentation de sa commande. Le deuxieme aspect de ce travail est l'etude et la realisation technologique de metallisations epaisses en surface de puces silicium pour l'hybridation en chip on chip de la partie commande et de la partie puissance. Ce memoire de these comporte trois chapitres equivalents : etudes theoriques et presentation des concepts, conception et validation experimentale de la partie commande puis conception de la partie puissance et developpements technologiques. Les champs d'application de ces travaux sont varies car ils couvrent un large domaine de l'electronique de puissance (convertisseurs hybrides).

A model for avalanche breakdown calculation in low-voltage trench power MOSFET devices

Abstract: In this work, the avalanche breakdown phenomenon in low-voltage trench power MOSFET is investigated through two-dimensional device simulations. The breakdown dependence from device geometrical characteristics is carefully characterized with particular attention to trench depth and drain region length and doping. An analytical model for breakdown calculation in a trench structure is presented. The analytical model is based on a well-known p+–n unilateral junction model, with a maximum electric field value correction to take into account the trench structure perturbation. It shows good results for a wide range of drift region characteristics and trench lengths.