What is CMP slurry?

What is CMP slurry?
CMP stands for Chemical Mechanical Polishing, which involves the simultaneous chemical dissolution and mechanical removal and polishing. The specific chemical action depends on the chemical properties of the material to be polished.
The abrasive particles used are relatively low in hardness and have particle sizes around 100nm, such as silica, alumina, and polymer beads. Therefore, it is difficult for distortion such as scratches and work-affected layers to enter the surface of the object to be polished.

Manufacturing Process

The production of CMP slurry requires dispersion technology. Dispersion technology refers to the technology to mix (disperse) particles uniformly into liquids, etc.

Disper type agitator
Disper type agitator
Stirring Dispersion:

By rapidly rotating stirring blades in a powder-liquid mixture, the shear force of the stirring blades breaks down aggregated particles and disperses them uniformly in the solution.
In the case of CMP, when using purchased silica or similar powders as abrasive particles, stirring dispersion prevents particle aggregation and minimizes the generation of scratches.
We have been manufacturing CMP slurry by leveraging our extensive experience in magnetic paint manufacturing. Through dispersion processes conducted in a cleanroom (Class 10000) and careful management of raw materials and equipment, we prevent contamination from heavy metals, bacteria, and other microorganisms to undetectable levels. For example, by protecting the interior of the slurry tank with a thick resin layer, the abrasive components in the slurry are prevented from wearing away the stainless steel parts of the tank, thereby avoiding the introduction of metal and metal ions and achieving strict contamination control suitable for precision processing.
We would like to share a video that provides a glimpse into the manufacturing process of CMP slurry, which is not commonly seen.Please take a look.
[Image of the interior of the slurry tank] 
スラリータンクイメージ

Thick resin layer prevents contact between slurry and stainless steel.

[Factory Tour]

Polishing methods using CMP slurry

Polishing of CMP involves holding a wafer, which is to be polished, in a carrier, applying pressure to the wafer, pressing the wafer onto a polishing Pad made of foam polyurethane, dropping the slurry, and performing polishing while rotating Pad and wafer.

Cu devices consist of an insulating film, copper (Cu) as the wiring metal, and a barrier film (typically Ta) to prevent Cu diffusion into the insulating film. In the first step of the polishing process, Cu is polished using Cu CMP slurry, and the process is stopped at the Ta surface. In the second step, Ta CMP slurry is used to polish both Ta and Cu.

Polishing equipment

The polishing equipment used in our experiments is the Applied Materials (AMAT) Mirra, which is similar to the equipment used in actual device manufacturing by device makers.
Polishing equipment 1
Polishing equipment 2
Polishing equipment 3

CMP slurry product lineup

We provide various types of CMP slurries.
We are good at polishing dissimilar materials with high or low selectivity, rather than polishing a single material.

Applications

Product name

Target material

Description

For copper devices and 3D wiring connections

TPC

Cu Silica slurry for copper wiring polishing in semiconductor devices.

MKT

Ta Silica slurry for barrier film polishing in semiconductor devices.

MKW

W Silica slurry for W contact plug.
For TSV SE-High
<Under development>
Thick film Cu Silica slurry for thick film Cu polishing
Cu high-speed removal on the order of microns
Si-07
<Under development>
Si Slurry for polishing the backside of Si substrate and TSV.
For resin polishing CME
<Under development>
Filler-filled resin-film Resin polishing slurry for build-up substrate
PI-01
<Under development>
PI, Cu Slurry for polyimide film and copper polishing
Others CMS
<Under development>
SiO2 Ceria slurry for semiconductor oxide film polishing
DS-01 Magnetic head
(AlTiC)
Oil-based diamond slurry
Good redispersion, achieves high-speed polishing with low scratching
Reduction of adherends to the polished object after polishing


Example of slurry development

We have developed various types of CMP slurries, mostly for metals and ceramics.
Here, we would like to introduce some examples other than those.

[Example: Resin Polishing Slurry]

History

A device manufacturer wanted to polish polyimide (PI) while stopping the polishing when reaching the surface of copper (Cu) plugs embedded in the polyimide. They approached us with this challenge. In addition, the polishing speed requires a micron-order polishing speed per minute, and we received a request to care about the surface roughness. Through polishing tests, we identified the appropriate particle type, particle size, pH, and reaction enhancers, and were able to achieve a good removal rate/Ra ratio, receiving positive evaluations compared to other companies' products. Since we have an evaluation device that can perform evaluation such as level difference measurement while polishing, we have led to such evaluation. Recently, there have been very many inquiries about this polyimide polishing slurry.

Good points

■Good polishing characteristics
 Composition designs (particle type, particle size, pH, and reaction enhancers) meeting customer requirements

■Evaluation equipments for polishing characteristics
・Step measuring machine, Film thickness measuring machine, AFM

Contract case for slurry manufacturing

We provide contract manufacturing services for various types of slurries and coatings.
If you have any manufacturing concerns, please feel free to contact us.

[Example: Water-based Slurry]

History

A battery materials manufacturer faced the challenge of preventing the contamination of conductive materials during their production process and reached out to us for a solution. The materials used in our manufacturing line consist of stainless steel for metals, with fluororesin layered on top of the metal. Additionally, we use fluororesin as much as possible for the liquid-contact parts. This allows us to minimize the introduction of metals and metal ions. Since we were a manufacturing line that cared for metal contamination, we were able to meet the requirements of the battery material manufacturers. Furthermore, as we manufacture products for the semiconductor industry, we have a track record of manufacturing in cleanroom environments, a well-established quality system, possession of various analytical instruments for property measurements, and most importantly, expertise in particle dispersion. These factors were highly valued, leading to our selection as a manufacturing partner. Although there was a need for rapid production within a short timeframe, we were able to leverage the expertise we have accumulated and quickly establish a production system. Currently, we continue to undertake manufacturing contracts without any quality incidents or delivery delays.

Reason for selection

■Enhanced facility environment
・Production in a cleanroom
・Quality assurance system
・In-house analysis/evaluation

■Years of experience in semiconductor product manufacturing

Cleanroom (air shower)

Cleanroom (air shower)

ICP

ICP


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