Visa's many semiconductor manufacturing determination of the concentration of H2O2 in tungsten CMP grinding fluid instrument supplier

Chemical mechanical polishing/polishing (CMP) is the chemical reaction and mechanical grinding together, is a costly and challenging important nano polishing process.This process is a key enabling step in integrated circuit manufacturing, impact on output and work efficiency.

Introduction of CMP

Polishing process using slurry containing antioxidants, antioxidant usually in the form of hydrogen peroxide (H₂O₂).In the process of manufacturing, wafer and polishing pad pressure closely together, at the same time make their respective counterclockwise with slightly different speed.Will paste shop in the center of the polishing pad, and then combined with the use of mechanical and chemical operation, gradually remove the material on the surface of the wafer, make local and overall smooth flat surface of a wafer.

At the factory before using CMP slurry to mix or diluted.Oxide polishing slurry is usually concentrated state, when buy water before use in the field, in order to reduce transport and Labour costs.Some multicomponent polishing slurry increases with the increasing use only, because the paste mixes in the period of validity is very short.To ensure that the correct mix is crucial, because the mixing effect is directly related to the chemical reaction rate and wafer polishing rate;Any defects in the process of mixing for manufacturability and reliability have a negative impact.Although manufacturing point (POM) slurry control is very strict, but subsequent process (including transportation, processing and filtering) will affect the chemical properties, so the need for continuous monitoring of slurry, until reach use point (POU), in order to ensure to achieve high yield.So you need to effective, fast, reliable, accurate and economic efficient of measurement tools and methods, so many manufacturers choose to use a refractometer.

How to use the refractive index measurement technology to improve production quality

Refractive index (RI) measurement technology is a kind of consumption slurry continuous on-line measurement method, can help the manufacturer fails the real-time information transfer process related quickly identify the pulp composition error, thus reducing the risk of a wafer.

CMP slurry with nanoparticles, the solid content of 1-30% (depending on the type of slurry), thus to analyze the concentration of hydrogen peroxide is extremely challenging.But through the calibration on the refractive index of a specific size and temperature characteristics, RI measurement method can not afraid the difficult conditions, successfully measure the tungsten hydrogen peroxide concentration in the slurry and the error control within + / - 0.03% (weight).

In addition, unlike the conductivity probe test, RI measurement can be used to detect H₂O₂Slurry concentration, the index can reflect the subsidence and degradation of the pulp with time.Therefore, RI is not only used for testing the quality of the products, also used in monitoring into the factory original size between the batch and verify mixed - add steps.

Parts of the slurry transport system has a conspicuous features, that is daily tank automatic chemical feed.

Visa, K - PATENTS ® semiconductor industry with the advantages of the refractometer

Visa, K ‑ PATENTS semiconductor industry with a refractometer designed for semiconductor manufacturing environment.The instrument size and do not contain metal, so suitable for chemicals in does not affect the process of measurement.

Visa, K ‑ PATENTS semiconductor industry with a refractometer for CMP operations, because:

• Digital measurement, and won't produce deviation
• Integrated temperature measurement component, RI measurement ensures high precision
• Can be directly density measurement
• Vibration in the process of design firm and reliable, affordable, reduce the error of measurement
• Through the built-in diagnostic procedures, can understand the process conditions immediately
• Has flow pool (designed to reduce or even eliminate the phenomenon of scaling).

reference

Over the years,DFS companyHas been used in the CMP operation visa K - PATENTS semiconductor industry with a refractometer, long term successful operation proves that the equipment is reliable and accurate."As the process node CMP steps are used more and more, we must ensure that delivery to polishing tools of pulp chemical properties and mechanical properties of stable," DFS chemical technology research and development director of companyKarl, UrquhartExplained, "RI online monitoring and assessment of the chemical composition of the feed, testing the quality of the mixed added step, and can be a not consumed pulp real-time measurement to verify whether the CMP slurry mixing."

In view of the CMP slurry H₂O₂Measuring devices in a large semiconductor factory in 2013 to complete installation, used to replace the automatic titration method.After installation, the measurement equipment and stable operation, and in addition to the normal wash slurry pool, need for instrument maintenance.

Usually, when installing a visa K - PATENTS semiconductor industry after using refractometer, manufacturers of wafer yield about 20%.In addition, CMP slurry under strict control, to improve the uniformity of the grinding process.