Gate-drain charge analysis for switching in power trench MOSFETs

For the switching performance of low-voltage (LV) power MOSFETs, the gate-drain charge density (Q/sub gd/) is an important parameter. The so-called figure-of-merit, which is defined as the product of the specific on-resistance (R/sub ds,on/) and Q/sub gd/ is commonly used for quantifying the switchi...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:IEEE transactions on electron devices 2004-08, Vol.51 (8), p.1323-1330
Hauptverfasser: Hueting, R.J.E., Hijzen, E.A., Heringa, A., Ludikhuize, A.W., Zandt, M.A.Ai
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext bestellen
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:For the switching performance of low-voltage (LV) power MOSFETs, the gate-drain charge density (Q/sub gd/) is an important parameter. The so-called figure-of-merit, which is defined as the product of the specific on-resistance (R/sub ds,on/) and Q/sub gd/ is commonly used for quantifying the switching performance for a specified off-state breakdown voltage (BV/sub ds/). In this paper, we analyzed the switching behavior in power trench MOSFETs by using experiments and simulations, focusing on the charge density Q/sub gd/. The results of this analysis can be used for further optimization of these devices. The results show that the Q/sub d/ can be split into three charge contributions: accumulation, depletion, and inversion charge. It is shown that the inversion charge is located mainly underneath the trench bottom. The accumulation and depletion charge contribute each about 45% in conventional LV trench MOSFETs and can be reduced by using a thick bottom oxide in a shallow trench gate just extending in the drift region. Further, we derived an analytical model for calculating the Q/sub gd/, that takes into account the geometry dependence.
ISSN:0018-9383
1557-9646
DOI:10.1109/TED.2004.832096