Industrial Ultra-Pure Water and Wastewater Treatment for the Semiconductor Industry from H+E

Introduction

For more than 40 years H+E has been a partner to the technology leaders in the semiconductor and solar cell industry and has accompanied and shaped significant technological advances for the needed water treatment systems during this time. In the case of the semiconductor industry H+E also adheres to its very practical approach and has developed its capability against the backdrop of a huge, acquired wealth of experience that has been gained in numerous successful projects. In each project with all customers worldwide.

Challenges of our Customers

Our production capacity will be expanded. We therefore require an extension of the water treatment while production continues

Our production is changed from 1 shift to 24/7. We therefore need to increase the availability of our water purification systems significantly.

We will introduce new products and will get new production processes. We therefore need a process or ultrapure water with a higher quality than before.

We will introduce new products and will get new production processes. Our wastewater composition will probably change.

The water authority has reported to an intensification of the discharge criteria for wastewater. What results are there for us?

We have been asked to search for cost saving potential. Can we realize this in our water treatment processes?

Applications

Pretreatment for the UPW Generation

The method combination best suited for ultrapure water production depends on the available raw water and the desired pure water quality in each individual case. The first stage of a HAGER + ELSÄSSER® plant consists of a SEMIPURE® pretreatment with a combination of processes tailored to the specific application. They usually include a multi-media filtration and softening of the feed raw water.

Make-up for the UPW Generation

The subsequent make-up process combination ROCEDIS.UPW generates the actual ultrapure water from the pretreated raw water. Here, too, in line with Hager + Elsässer’s individual approach philosophy, the company’s specialists always develop the process solution that corresponds exactly to the particular ultrapure water qualities desired by the client. For example, reverse osmosis, membrane degassing, EDI, UV treatment, and, if necessary, also a mixed bed filter come into play here.

Polishing for the UPW Generation

The final stage of UPW production consists of a loop system, the so-called SEMICIRCLE, by means of which the obtained ultrapure water is distributed to its various operating units. This system also includes polishing, i.e. refreshing and maintaining the necessary ultrapure water quality by means of a UV treatment, a membrane degassing, the use of a mixed bed polisher and a final ultrafiltration.

Process Water Treatment for Semiconductor and Solar Cell Production

The large quantities of ultrapure water used in the semiconductor industry naturally lead to correspondingly high amounts of wastewater from the production processes. One differentiates between wastewater streams with low TOC contents and those with high TOC concentrations of organic components. The former result from the final rinsing processes of the wafers, while wastewaters of the latter kind accrue in various other cleaning processes and processing baths. In both cases, the plants are individually adapted to the wastewater compositions.

Rinsing Water Reclaim for Semiconductor and Solar Cell Production

The large quantities of ultrapure water used in the semiconductor industry naturally lead to correspondingly high amounts of wastewater from the production processes. One differentiates between wastewater streams with low TOC contents and those with high TOC concentrations of organic components. The former result from the final rinsing processes of the wafers, while wastewaters of the latter kind accrue in various other cleaning processes and processing baths. In both cases, the plants are individually adapted to the wastewater compositions.

HF-Wastewater Treatment for Semiconductor and Solar Cell Production

In etching processes, large volumes of hydrofluoric acid are used which are then contained in the wastewater. For this reason, the wastewater is treated by precipitation and flocculation. By addition of lime milk or calcium chloride, the fluoride contained in the waste water in the form of calcium fluoride is precipitated. The calcium fluoride sludge produced is dewatered and disposed of. H + E individually designs the necessary process line on the basis of parameters such as throughput and fluoride concentration.

CMP-Wastewater Treatment for Semiconductor Production

Wastewaters resulting from the planarization of the wafer surfaces contain on the one hand the grinding aid itself, and on the other hand high concentrations of particulate matter caused by the abrasive wear. Both are effectively removed by precipitation and flocculation. The resulting sludge is dewatered and disposed of. H+E individually designs the process line on the basis of parameters such as throughput and particle concentration.

Copper CMP Wastewater Treatment for Semiconductor Production

Wastewaters resulting from the planarization of the wafer surfaces contain on the one hand the copper-containing grinding aid itself, and on the other hand high concentrations of particulate matter caused by the abrasive wear. Both are effectively removed by precipitation and flocculation. The resulting metal-containing sludge is dewatered and disposed of. Selective ion exchangers downstream remove the residual concentrations of copper.
H + E individually designs the process line on the basis of parameters such as throughput and particle concentration.

Neutralization for Semiconductor and Solar Cell Production

Generally, the treated wastewaters from the aforementioned partial flow treatments are not yet within the pH range permitted for discharge. Along with other low contaminated rinse waters, they therefore pass through a multi-stage neutralisation before they are discharged into the sewer.

Hook-up and Special Services for Semiconductor and Solar Cell Production

H+E not only provides plants for the production of ultrapure water, but also the distribution systems (loop), including the connection to the consumer (hook-up). Likewise, H + E provides the wastewater manifolds (drains), including the connection to the wastewater generating tools, as well as complete systems for collecting spent acids or solvents.