International Business Machines Corporation

Gottlieb S Oehrlein

Thao Ngoc Nguyen

Zeev A Weinberg

Ying Di Zhang

Gary W Rubloff

Marco Haverlag

David Vender

Alfred Grill

David Louis Harame

Vishnubhai Vitthalbhai Patel

Rodney T Hodgson

Maurizio Arienzo

The present invention relates to a method and apparatus for etching semiconductor devices where the undesirable deposition of films on the internal surfaces of the apparatus are prevented during the etching process. The system for etching devices provides an etching chamber having a deposition resistant surface, a holder for holding the device to be etched, and a heater for heating the deposition resistant surface to a temperature between 100.degree. C. to 600.degree. C. to impede the formation of films on the walls of the chamber. The etching system may further include the deposition resistant surface surrounding the holder while not interfering with the plasma used to etch the substrate.

Apparatus for hot wall reactive ion etching using a dielectric or

The adhesion between a polymeric fluorocarbon film and a substrate is improved by providing a non-volatile carbide-forming metallic layer intermediate the substrate and the polymeric fluorocarbon film, and exposing the substrate to ion-bombardment in a noble gas/polymerizing gas atmosphere prior to providing the fluorocarbon films.

Promotion of the adhesion of fluorocarbon films

The present invention relates to a method and apparatus for etching semiconductor devices where the undesirable deposition of films on the internal surfaces of the apparatus are prevented during the etching process. The system for etching devices provides an etching chamber having a deposition resistant surface, a holder for holding the device to be etched, and a heater for heating the deposition resistant surface to a temperature between 100 C to 600 C to impede the formation of films on the walls of the chamber. The etching system may further include the deposition resistant surface surrounding the holder while not interfering with the plasma used to etch the substrate.

Method for hot wall reactive ion etching using a dielectric or metallic

The adhesion between a polymeric fluorocarbon film and a substrate is improved by providing a thin layer of silicon or a silicide intermediate between the substrate and the polymeric fluorocarbon film, such that a region containing a high density of Si-C bonds is formed.

Adhesion promotion of fluorocarbon films

The present invention is a structure and method for controlling the depth of an etching process. In particular, the method and structure of the present invention creates a marker layer which resides between a layer to be etched and a protected layer. The marker layer is detected during the etch process and the etch process is controlled based on the detection of the marker layer. The marker layer has physical characteristics which are very similar to the layers being etched or protected. The marker layer has a similar lattice constant and electrical behavior to either the etched layer or the protected layer. The marker layer has very different optical properties from the etched or protected layers so that even a thin marker layer can be easily detected using in-situ ellipsometric measurements. A specific embodiment of the present invention is a layer of SiGe interposed between a thick silicon layer and a thin silicon layer. In particular, the SiGe layer has a composition of approximately 10% of germanium and has a thickness of approximately 10.ANG.. The thick silicon layer has a thickness of approximately 5,000.ANG. and the thin silicon layer has a thickness of approximately 1,000.ANG.. A method of etching the thick silicon layer, incorporating one embodiment of the present invention, is to perform a RIE process on the thick silicon layer while monitoring the RIE process with an ellipsometer. When the RIE process encounters the underlying marker layer, the ellipsometer measurements show a marked change. The marked change in the ellipsometer measurements indicate when to stop the RIE process. When the marker layer is very thin, such as 10.ANG., the RIE process is stopped immediately and the underlying thin silicon layer is not etched into. Even though the RIE process is not uniform, and parts of the marker layer will remain on the surface of the protected layer, this will not affect the electrical behavior of the resulting semiconductor device using this process. This is because the thin SiGe marker layer has electrical characteristics which are very similar to the underlying silicon layer.

Method for controlling silicon etch depth

Polymeric fluorocarbon layer is prepared by plasma enhanced chemical vapor deposition in a chamber, the walls of which are coated with a polymeric fluorocarbon film by introducing a gaseous polymerizable fluorocarbon into the chamber and applying radio-frequency at a power level of about 100 to about 1000 watts, employing a pressure of about 10 to 180 mTorr and a self-bias voltage of about -50 to about -700 volts. The polymeric fluorocarbon layer is about 0.05 to about 5 .mu.m thick, has a maximum dielectric constant of about 2.5, has a C/F ratio of about 1:1 to about 1:3, is thermally stable at temperatures of at least about 350.degree. C., and is substantially free from metallic contamination and oxygen.

Plasma deposition of fluorocarbon

The invention provides a capacitor having increased capacitance comprising one or more main vertical trenches and one or more lateral trenches extending off the main vertical trench. The capacitor has alternating first and second regions, preferably silicon and non-silicon regions (for example, alternating silicon and germanium or alternating silicon and carbon regions). The etch characteristics of the alternating regions are utilized to selectively etch lateral trenches thereby increasing the surface area and capacitance of the capacitor. A method of fabricating the capacitors is also provided.

High area capacitor formation using material dependent etching

The invention provides a method of increasing the capacitance of a capacitor which comprises forming a capacitor having a main vertical trench and one or more lateral trenches extending off the main vertical trench. The capacitor has alternating first and second silicon regions, for example n-doped and p-doped silicon regions. After a main vertical trench is dry etched through the first and second silicon regions, the etch characteristics of the alternating first and second silicon regions are utilized to selectively dry etch lateral trenches, thereby increasing the surface area of the capacitor and the capacitance of the capacitor. Capacitors produced by this method are also provided.

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Yorktown Heights, NY, United States of America

Gottlieb S Oehrlein