International Business Machines Corporation

Siemens Aktiengesellschaft

Infineon Technologies Ag

Klaus Dieter Penner

David Lee Rath

K Paul Muller

Mirko Vogt

Kamalesh K Srivastava

Klaus-Dieter Morhard

Susan L Cohen

Hans-Peter Sperlich

Irene Sperl

Barbara Lorenz

Wilhelm Claussen

Emmanuel I Cooper

A method for increasing a trench capacitance in deep trench capacitors is described, in which, in a standard method, after the etching of the arsenic glass, a wet-chemical etching is additionally performed. An n&plus;-doped substrate results from the driving-out of the arsenic glass being widened in the trench, by about 20 nm, selectively both with respect to the lightly doped substrate and with respect to the oxide layer and with respect to the nitride layer.

Method for increasing the trench capacitance

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

A process for monitoring and determining the end point of a wet etch process for removing a thin solid film 116 from a substrate by directing a light beam onto the substrate and monitoring the intensity of reflected beams, including the step of selecting a coherence length of the incoming beam 120 so that it is small enough so that no interference occurs in the liquid layer and large enough so that interference can occur in the thin solid film, i.e., light reflected from the interface between the liquid 118 and the top of the thin film, and light reflected from the interface between the bottom of the thin solid film and the substrate interferes. If the liquid layer is about 100 micrometers thick, and the thin film is about 1 micrometer thick, a coherence length of about 10 micrometers is suitable. Such coherence length can be provided with a suitable bandpass filter.

Method of end point detection using a sinusoidal interference signal for

An efficient cleaning process of microelectronics devices requires lower levels of megasonic power, lower temperature and much lower concentrations of chemicals. The method controls the effectiveness of megasonics-assisted cleaning of microelectronics devices by securing a gas concentration level in the cleaning solution, such that at the process temperature the solution is partially saturated with the gas. The gas concentration can be controlled either at the plant-wide level or, preferably, at the point of use. In the latter case, two water supply inputs are provided, one of vacuum-degassed water and the other of gas-saturated water. Process water in the desired gas concentration is then obtained by mixing water from the two sources in an appropriate ratio, which resulting mixture is fed to the wafer cleaning vessel.

Control of gas content in process liquids for improved megasonic

Growing community of inventors

Ottendorf-Okrilla, Germany

Klaus Dieter Penner