The Library

Modeling the impact of the trench depth on the gate-drain capacitance in power MOSFETs

Tools

Alatise, Olayiwola M., Parker-Allotey, Nii-Adotei, Jennings, M. R., Mawby, P. A. (Philip A.), Kennedy, Ian and Petkos, George. (2011) Modeling the impact of the trench depth on the gate-drain capacitance in power MOSFETs. IEEE Electron Device Letters, Vol.32 (No.9). pp. 1269-1271. ISSN 0741-3106

Preview

Text
WRAP_Alatise_IEEE_EDL_Switching_Losses_paper_FINAL.pdf - Accepted Version
Download (530Kb)

Official URL: http://dx.doi.org/10.1109/LED.2011.2159476

Abstract

Trench depth is important in low-voltage trench MOSFETs because it affects the switching losses through the gate-drain capacitance (C(GD)). The dependence of C(GD) on the trench depth is investigated by analytical modeling and experimental characterization. An analytical model that relates the trench depth, trench bottom oxide thickness, n(-) layer doping, and drain voltage (V(D)) to C(GD) is developed and validated by experimental measurements. Trench MOSFETs with thick bottom oxides have been fabricated with 1.3-, 1.5-, 1.7-, and 2-mu m deep trenches. CV measurements show that C(GD) is proportional to the trench depth at low V(D) and becomes increasingly independent of trench depth as V(D) is increased. The model is used to show that this is due to C(GD) being dominated by the oxide capacitance at low V(D) and the depletion capacitance at high V(D). The fact that the average thickness of the trench bottom oxide decreases as the trench depth increases (because of additional sidewall oxide overlapping the drain) means that the impact of the trench depth is the highest at low V(D), where the depletion capacitance is ineffective.

Item Type:

Journal Article

Subjects:

T Technology > TK Electrical engineering. Electronics Nuclear engineering

Divisions:

Faculty of Science > Engineering

Library of Congress Subject Headings (LCSH):

Metal oxide semiconductor field-effect transistors -- Mathematical models

Journal or Publication Title:

IEEE Electron Device Letters

Publisher:

IEEE

ISSN:

0741-3106

Official Date:

September 2011

Dates:

Date	Event
September 2011	Published

Volume:

Vol.32

Number:

No.9

Number of Pages:

Page Range:

pp. 1269-1271

Identification Number:

10.1109/LED.2011.2159476

Status:

Peer Reviewed

Publication Status:

Published

Access rights to Published version:

Restricted or Subscription Access

Funder:

Advantage West Midlands (AWM), Birmingham Science City

References:

[1] Shinohara, “Analysis of Power Losses in MOSFET Synchronous
Rectifiers by using Their Design Parameters”, in Proc of ISPSD,
pp.347-350, 1998.
[2] R Hueting, E Hijzen, A Heringa, A Ludikhuize and M Zandt, “Gate-
Drain Charge Analysis for Switching in Power Trench MOSFETs”,
IEEE Trans. Electron Devices, vol. 51, no. 8, pp. 1323-1330, 2004.
[3] M Darwish, C Yue, K Lui, F Giles, B Chan, K Chen, D Pattanayak, Q
Chen, K Terrill and K Owyang, “A New Power W-Gated Trench
MOSFET (WMOSFET) with High Switching Performance”, ISPSD,
pp.24-27, 2003.
[4] J Baliga, “Fundamentals of Power Semiconductor Devices”, Springer,
2008.
[5] O Alatise, I Kennedy, K Heppenstall, G Petkos, K Khan, A Koh, J
Parkin and P Rutter, “The Impact of Repetitive Unclamped Inductive
Switching on the Electrical Performance of Low Voltage Discrete
Power Trench MOSFETs”, IEEE Transactions on Electron Devices,
vol. 57, no 7, pp.1651-1658, 2010.