Semiconductor device with cell trench structures and recessed contacts and method of manufacturing a semiconductor device

US10629676B2 · kind B2 · utility

Assignee

• Infineon Technologies AG · DE

Inventors

• Johannes Georg Laven · Taufkirchen, DE
• Maria Cotorogea · Taufkirchen, DE
• Hans-Joachim Schulze · Taufkirchen, DE
• Haybat Itani · Villach, AT
• Erich Griebl · Dorfen, DE
• Andreas Haghofer · Villach, AT

Key dates

• Filing date: Aug 23, 2018
• Grant date: Apr 21, 2020
• Expiry date: Aug 23, 2038

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D64/513
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

First and second cell trench structures extend from a first surface into a semiconductor substrate. The first cell trench structure includes a first buried electrode and a first insulator layer between the first buried electrode and a semiconductor mesa separating the first and second cell trench structures. A capping layer covers the first surface. The capping layer is patterned to form an opening having a minimum width larger than a thickness of the first insulator layer. The opening exposes a first vertical section of the first insulator layer at the first surface. An exposed portion of the first insulator layer is removed to form a recess between the semiconductor mesa and the first buried electrode. A contact structure is in the opening and the recess. The contact structure electrically connects both a buried zone in the semiconductor mesa and the first buried electrode and allows for narrower semiconductor mesa width.