LDMOS with guard ring (of same type as drain) surrounding the drain

US6933559B1 · kind B1 · utility

Assignee

• KONINKLIJKE PHILIPS ELECTRONICS NV · NL

Inventors

• Raymond Van Roijen · Hopewell Junction, US
• Johannes Hendrik Hermanus Alexius Egbers · Nijmegen, NL
• Adrianus W. Ludikhuize · Eindhoven, NL
• Anco Heringa · Eindhoven, NL

Key dates

• Filing date: Sep 18, 2000
• Grant date: Aug 23, 2005
• Expiry date: Jan 29, 2021

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D64/516

Abstract

In high-voltage devices comprising a lightly doped region (3) provided with a heavily doped contact zone 4, damage caused by local breakdown at the corner of the contact zone may occur as a result of the Kirk effect at a high current density. To improve the robustness of the device, an annular protection zone (14) of the same conductivity type is provided so as to surround the contact zone at a small distance. As a result, breakdown will occur initially at the corner of the protection zone. However, due to the resistance between the protection zone and the contact zone, a more uniform current distribution is obtained, which prevents damage caused by local current concentration.