Siemens Aktiengesellschaft

Egon Bussmann

Hubert De Steur

Jacky Vanhumbeeck

Wolfgang Pernegger

Johannes Helder

Walter Pritzl

Bruno Flamme

A limit is placed on the miniaturization of the field oxide structures in the manufacture of semiconductor layer arrangements due to the length of the thick oxide bird's beak. The diffusion of oxidizing agent is suppressed according to the invention by means of a thin diffusion barrier of silicon nitride which also produces no crystal faults in the desired temperature range. The natural oxide on the silicon wafers is also converted into a diffusion barrier as required by means of nitrogen implantation and/or special process management in the nitride deposition.

Preventing lateral oxide growth by first forming nitride layer followed

A process control circuit which is adapted for the control and monitoring of a plurality of parameters in one or more metal-depositing baths, has parameter control circuit blocks for each of the parameters to be measured. Each of the parameter control circuit blocks has a measuring stage for producing a measured value corresponding to one of the parameters, a calibration stage for calibrating the measuring stage, a comparison stage for comparing the measured value to a stored nominal value, and a dosing circuit which is connected to the comparator and which doses the metal-depositing bath in response to a comparison signal from the comparator.

Process control circuit for metal-depositing baths

A process control system for metal depositing baths for monitoring the chemical composition of a bath liquid provides that, in the event of a deviation of a component of the bath liquid from a reference value, the bath liquid is regenerated by supplying correcting liquid to the bath. The system includes an automatically operating analyzer which is connected to a measured value adjusting device which, in dependence upon the difference established between a reference value and an actual value of the bath liquid component subject to analysis, controls the supply of the correcting liquid to the bath. A common process control system for a plurality of galvanic baths includes a main programmer, a bath selection programmer and analysis programmers which can be selectively connected by the selection programmer, and which in accordance with the individual components of the bath liquid which is to be analyzed, actuate specific analyzer sections of the analyzer where each measured value adjusting device which is connected to an analyzer section will, in the case of a difference in measured value, control the supply of the correct quantity of the specific correcting liquid to the particular bath which is subject to analysis.

Process control system for the automatic analysis and regeneration of

Process and apparatus for automatic checking and control of etching machines which provides a signal related to the strength of the etching solution and provides means whereby the length of etching time can be varied in relation to the concentration of the etching solution. The present invention provides a system including a measuring compartment through which an etching solution from the etching machine is constantly circulated. A measuring wire is inserted into the measuring compartment and held stationary therein for a time sufficient to cause the etching solution to etch away an end portion of the wire. The time required to etch off this end portion is measured and provides an analog signal of etching solution strength which is proportional to etching time. This signal can be used to control the feed of the etching machine so that as the solution becomes less concentrated, the time of exposure of the material being etched is increased.

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Munich, Germany

Egon Bussmann