Wacker-chemitronic Gesellschaft Fur Elektronik-grundstoffe Mbh

Ingolf Lampert

Herbert Jacob

Reinhold Wahlich

Christa Gratzl

A process for the wet-chemical surface treatment of semiconductor wafers in which aqueous phases containing one or more chemically active substances in solution act on the wafer surfaces, consisting of spraying a water mist over the wafer surfaces and then introducing chemically active substances in the gaseous state so that these gaseous substances combine with the water mist so that there is an interaction of the gas phase and the liquid phase taking place on the surface of the semiconductor wafer. Gases such as hydrogen fluoride, chlorine and ozonized oxygen or other halogen gases act on the wafer surfaces between rinsing steps so that when the wafers are dried, the surfaces achieve extremely high cleanliness levels.

Process for the wet-chemical surface treatment of semiconductor wafers

The invention relates to an improved method for removing point defects and oint defect clusters from semiconductor discs, which defects impair the quality of electronic components or structural elements made from such discs. According to the invention, prior to polishing, the semiconductor discs are immersed in a bath containing grains moving in a streaming carrier medium of the bath. One side of the discs are then polished and thereafter the discs are subjected to oxidation processes whereby stacking faults are induced in the rear side of the discs. These stacking faults have an excellent gettering effect on the point defects.

Process for the removal of specific crystal structures defects from

In a process for protecting polished silicon surfaces, after an oxidative eaning is carried out, the surface is coated with a protective layer by the action of a reagent especially hexamethyldisilazane which permits trialkylsilylation. The layer prevents aging of the oxide layer even over several months storage. Before subsequent processing steps, the protective layer can easily be removed again by thermal oxidation, without forming interfering by-products.

Process for protecting polished silicon surfaces

A process for polishing silicon wafers includes the step of carrying out last polishing step in the polishing operation in such a way that a protective film of silicon dioxide is produced on the surface of the polished wafer. The film does not interfere with e.g., the subsequent oxidation processes. The protective film protects the wafer surface from the many effects arising in subsequent processes which may unfavorably influence the quality of the surface.

Process for polishing silicon wafers

Surfaces of III-V-semiconductors, especially gallium phosphide surfaces, can be polished very successfully if, in the polishing operation, an alkali metal hypochlorite solution adjusted to a pH value of from 8.5 to 11 by the addition of buffering components, and a liquid containing in addition to the mechanical polishing component a complex-forming component, are applied to the surface to be polished.

Process for polishing III-V-semiconductor surfaces

Process for producing haze free semiconductor surfaces, especially surfaces of (111)-oriented gallium arsenide, by polishing, which comprises subjecting the surfaces to the polishing action of a mixture of (a) an aqueous suspension containing one or several polishing agents selected from quartz, silica, a silicate and a fluosilicate, and having a pH within the range of from 6 to 8 and, (b) an aqueous solution of hydrogen peroxide having a pH likewise ranging from 6 to 8, the latter being present in an amount of 2 to 15% by weight of H.sub.2 O.sub.2. The invention also relates to the haze free semiconductor surfaces so made.

Process for preparing haze free semiconductor surfaces and surfaces so

Process for polishing semiconductor surfaces, especially gallium phosphide urfaces, with an aqueous suspension of aluminum and/or gallium hydroxide precipitated from the elements by an alkaline compound at the pH value between 7.5 and 8, the suspension further containing an alkali hypochlorite in such an amount that in addition to 0.05-0.6 mol hydroxide per liter, the molar content of hypochlorite will be three to ten times that of the hydroxide; the surfaces are subjected to a buffing action with said suspension. The invention also relates to the polishing agent used in the process.

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Burghausen, Germany

Ingolf Lampert