In-Line Carbon Dioxide Infuser
Built to be installed in series with the DI water flow path, this compact infuser has its innovation hidden inside the sealed infusion chamber. Utilizing a lower cost but high purity hydrophobic membrane in combination with a housing manufactured to optimize the efficiency of gas transfer the infuser performance is maximized. Our infusers can be manufactured in 14 or 24 inch chamber lengths depending on your particular PH response needs for the tank size in your system. Process optimization is generally achieved through the proper utilization of a combination of infusion products. By utilizing our integral tank and in-line infuser products carbon dioxide diffusion and static charge neutralization is maximized.
Infusion contractors are available in Natural Polypro, PVDF/Kynar and Halar depending on your particular infusion gas requirements or DI water temperature. Membrane protection devices are available and where used will greatly extend the life of the contractor assembly. These regulators will balance the pressure delta between the gas and DI water to maximize diffusion efficiency while protecting the membrane from rupture and fluid permeation.
Trench Etch Damage -Source Qcept Technology
Considerable debate continues as to the various causes of yield loss in the center regions of some production wafers. However ESD “Electro Static Discharge” events are clearly a major contributor to yield losses in circular patterns around the center area with some devices.
This yield loss can be eliminated with the proper utilization of CO2 infusion into De-ionized ultra pure water. “ESD” events within rinse water tanks have caused considerable damage to traces and general circuit structure. Often this damage is in the form of pits created by the discharge itself. These pits are commonly referred to as “Bullet Holes” due to their similarity in appearance.
BeOL CO2 DI Rinse
When removing residual solvent from photoresist strippers containing alkaline such as EKC-265 or ACT-CMI often Isopropyl Alcohol is utilized. Although effective the costs associated with the purchase and disposal make this method of rinsing less then ideal. Consistency of the rinse is also quickly affected by the rapid buildup of resist stripper within the Isopropyl Alcohol. When these issues combine with the complications of exhausting evaporated IPA and EPA regulation compliance the need to eliminate IPA rinsing becomes clear. Amine based Resist stripper solutions can also be rinsed with DI water but the corrosion of exposed Aluminum traces or pads can become a serious problem. This is primarily caused by the reaction of the amine based solutions with DI water. When combined the amines become caustic driving up PH levels causing the damage.
Corrosion On Al Pads
This pitting and corrosion of the lands and pads can be eliminated through the proper use of CO2 injection prior to and during the DI water rinse steps. By employing the proper utilization of CO2 gas large PH swings from the reaction can be effectively countered in a way that actually helps promote the effective rinsing of the residual stripper. Typical rinse times of five to ten minutes provide adequate rinsing providing a more environmentally friendly and cost effective rinse process.