# Presentation: 013088

## NM Water Conservation Alliance Roundtable Discussion

***Reducing Water Usage in Semiconductor Manufacturing***
***March 23, 2000***
***Rio Rancho,NM***

## Experience with a Recycle DI System

***Kurt Eckert***
***EEEE***
***951 Amsterdam Dr.***
***Colorado Springs, CO 80907-4034***
***eckertk@asme.org***
***719-590-7133***

## Contributors		

***System design - Jacob’s Engineering***
***Manufacturer - Glegg Water***
***Atmel Project Manager - Kurt Eckert***

## Objective

***What is DI recycle vs. DI reclaim?***
***Why is DI recycling necessary?***
***Why was this recycle system installed?***
***What are the hurdles for a recycle system?***
***Review the system design***
***Share actual operating***
***   ******experience***

**Notes:**
This talk is focused on the system I was the project manager on, with a few generalizations thrown in .

## A recycle system

***Collects a portion of the drains from process tools and reprocesses it back to a quality to be*****:**
*Reintroduced back at some point in the primary UPW system*
*Reutilized for a lower quality DI system such as CMP or central clean*

**Notes:**
This is the most risky of options

## A Reclaim System

***Collects a portion of the drains from process tools and may or may not reprocess it back to a quality to be*****:**
*Used in other applications such as: *
*boilers*
*cooling towers*
*scrubber make up*
*irrigation*

**Notes:**
This is more common and involves less risk

## Recycle/reclaim graphically

- Primary UPW System

- Fab UPW Utilization

- Fab Drains

- Recycle

- Reclaim

- Make-up water

- Boilers, Scrubbers, Cooling Towers

- Evaporation

- WWT

## Why is recycling necessary

***Sematech (1995)- 2,275 gallons of water to process one 6 inch (150 mm) wafer***
***Semiconductor Industry (1996)- 8” wafers increase water consumption by 250% , over 6” wafers***
***Cleanrooms (1996)- Projects 7X increase in UPW consumption for 300mm      wafers over 200mm wafers***

## Why was this recycle system installed

***Fab expansion required more UPW capacity***
***WWT system did not have any capacity margin***
***City sewer line was at capacity***
***Lower first cost***

**Notes:**
Now we’ll focus in more on this project

## Major hurdles

***Fear (paranoia) about contamination of DI system (TOC’s)***
***Financial, payback ***
***Notion that water resources are without limit***
***Space***

## Design considerations for this system

***Collect water only from the best sources.  No solvent hoods.***
***Monitor TOC’s early in collection system with ability to dump on high TOC’s***
***Install a system to remove TOC’s***

**Notes:**
Have slide of time line for RAT analysis

## Design considerations for system (cont.)

***Monitor TOC’s in final product with ability to dump before introducing into the UPW system ***

## Schematic of Recycle system

**tank**

**Transfer**
** ****tank**

**Analysis**
** ****tank**

***Schematic of Recycle system***

**Analysis**
** ****tank**

**WWT**

**Drains**

**m****s**

- High

- Low

**TOC**

- High

- Low

-   **sodium**
**hydroxide**

**Hydrogen**
**Peroxide**

**City water backup**

-   **sodium**
**hydroxide**

**sodium**
**bisulfite**

**WWT**

**185 ****h****m**

-       **TOC Destruct UV**

-   **filter .1****m****m**

**CMP**

**Quartz Clean**

**WWT**

**Recycle to RO storage tanks UPW system**

**TOC’s**

-     **Electro-Deionization**

- Low

- Manual    Valve

**Reuse**
** ****boilers, scrubbers**

**Advanced Oxidative Process**

**RO**

**filter 1****m****m**

**Cooling Heat Exchanger**

## Actual Operating Data (TOC’s)

**Analyzer A      TOC’s        0-2000 ppb**

**Recycle     TOC’s        0-50 ppb**

**Analyzer B    TOC’s        0-2000 ppb**

## Actual Operating Data (conductivity)

- Drain Conductivity     0-500 mS

- Recycle    resistivity            0-20 mW

**Drain      Flow           0-200 GPM**

**Notes:**
90 GPM 85% RO recovery 95% CEDI recovery
38 M gallons/year

## Operating Experience

***Need to work with Line Maintenance and Production personnel ***
*Explain what the system does and how solvents impact the system*
*Label each piece of equipment *
*Repeat every 6 months*
***Also, need to work hand in hand ***
***	******with operators***

**Notes:**
Have slide of time line for RAT analysis

## Operating Experience (Cont.)

***There was a significant reduction in primary regenerations saving:***
*manpower*
*chemicals*
*water*
***CEDI is not ready for polishing loop applications***

## Final Thoughts

***The skeptics watch you closer and expect more of you when you have a recycle system***
***People are amazed at how much water (read $$$) are saved***
***The experience has been:***

*Scary*
*rewarding**	*

*Frustrating*
*exhilarating*