THE PRODUCTION OF ULTRAPURE WATER (DIW) IN SEMICONDUCTOR AND MICROELECTRONICS MANUFACTURING
The technologies involved in the development of new generations of semiconductors, which are evolving rapidly, require the use of process fluids of increasingly high quality. Among these, ultrapure water (DIW) represents one of the most critical elements. In fact, it is used in significant volumes during the essential rinsing phases of chip manufacturing processes.
Achieving such demanding objectives is based on the availability of sophisticated and complex technology combined with specific know-how, representing the integration of the following elements:
Perfect knowledge of process steps
Excellence in design
Expertise and quality in construction
System flexibility
Reliability and safety in operation
These objectives are continuously pursued through Research and Development (R&D) activities carried out by a “Total Quality Management Team” (TGMT), established within Elettracqua.
The configuration of an ultrapure water production system depends on two main factors:
The chemical and physical characteristics of the incoming water
The required quality specifications
For example, for the production of 64 MBit memory chips, the required DIW quality is as follows:
Resistivity > 18.2 megaohms/cm
TOC < 5 ppb
Particle size > 0.1 μm < 1000/l
SiO₂ < 3 ppb
Based on our company’s many years of experience, the treatments required to produce water suitable for 64 MBit chip manufacturing are at least the following:
Pre-treatment with Dual Media Filter, Softening, or alternatively an Ultrafiltration (UF) system
Primary purification with reverse osmosis, UV 254 nm, and degassing membranes
Fine purification (make-up) with EDI
Final polishing with UV treatment and reduction of the final TOC value