Method for monitoring ion implantation doping concentration

Abstract

The invention discloses a method for monitoring ion implantation doping concentration. The method comprises the following steps: fusing ion implantation operation into any half surface of an MOS structure substrate slice so that two sides of the surface of a test area are of different doping concentrations, further testing quasi-static C-V characteristic and high-frequency C-V characteristic on two sides, and calculating flat belt voltage difference values on two sides of the surface; under the same technological condition, carrying out a plurality of groups of parallel tests for different ionimplantation dosages so as to obtain a plurality of flat belt voltage difference values, wherein functional relationships between the flat belt voltage differences values and the ion implantation dosages can be matched in combination with the flat belt voltage difference values and corresponding ion implantation dosage data; according to the same technological process, carrying out ion implantation operation on an area D1 in one half of the substrate slice to be monitored and an area D2 in the other half of the substrate slice to be monitored to obtain corresponding flat belt voltage difference values delta VoFB, substituting the VoFB into the functional relationships between the flat belt voltage differences values and the ion implantation dosages so that the doping concentration of boron ions or phosphorus ions actually introduced into the substrate slice to be monitored through ion implantation can be solved determined.

Description

technical field [0001] The invention relates to doping monitoring in the manufacture of semiconductor integrated circuits, in particular to a method for monitoring ion implantation doping concentration. Background technique [0002] In the manufacture of semiconductor integrated circuits, ion implantation is usually used to modulate the impurity doping concentration and junction depth in specific regions to meet product parameter requirements. Therefore, ensuring the consistency of the injection dose of boron and phosphorus impurities on-line plays a key role in the stability of the product process. Especially for the small line width product process, the doping concentration on the product surface is usually low. If the surface of the product is contaminated by a small amount of boron and phosphorus impurities or the ion implantation conditions fluctuate during the tape-out process, the threshold voltage and breakdown characteristics of the device may be abnormal. . There...

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Problems solved by technology

At present, there is no report on the use of this principle to monitor the concentration of doped impurities.

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