Infineon Technologies Ag

Siemens Aktiengesellschaft

Barbara Lorenz

Mirko Vogt

Dietmar Temmler

Christian Drabe

Matthias Foerster

Hans-Peter Sperlich

Anke Krasemann

Bruno Spuler

Thomas Morgenstern

Klaus Dieter Penner

Jana Haensel

Wilhelm Claussen

Daniel Koehler

Torsten Schneider

A method teaches how to fill trench structures formed in a semiconductor substrate. The trench structures are coated in a first deposition process with a first primary filling layer with a high conformity and minimal roughness. A V etching reaching down to a predetermined depth of the trench structure is subsequently performed in order to produce a V-profile.

Method for filling trench and relief geometries in semiconductor structures

A two-step etch process is used to form a vertical collar oxide within the upper portion of a trench capacitor. The first step uses CF/SiF/Ochemistry and ends when the bottom of the collar within the trench is opened although a thin oxide layer still remains on the surface of the PAD-nitride. The second etch step uses CFchemistry to completely remove the remaining silicon oxide layer. The process provides a good uniformity in thickness of the PAD-nitride layer and sufficient collar oxide thickness in the very top section of the collar oxide. The process is applicable for manufacturing deep trench capacitors for DRAM devices.

Method of forming an isolation layer and method of manufacturing a trench capacitor

An antireflection layer, preferably a dielectric antireflection layer, is applied by PECVD to a hard mask layer which is composed of doped silicon oxide, with no interruption of the vacuum. The silicon oxide layer is then patterned to form a hard mask and, by way of example, a deep trench etching is performed. The hard mask is removed using an HF/H,SO,mixture or using an HF/ethylene glycol (EG) mixture at a high etching rate. If the HF/EG mixture is used, an intermediate layer that may be disposed underneath can simultaneously be etched back by a predetermined amount. The integration of two wet etching steps constitutes a major simplification compared with the previous wet etching methods in two different installations.

Method for fabricating a semiconductor structure

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Dresden, Germany

Barbara Lorenz