Why a water fine filter can result in problems
Water that is used in microelectronics should contain no particles. Fine filters are widely used to improve wet etch equipment performance. The filter is expected to reduce the number of particles in the water.
The number of particles is defined by measuring the number of defects on a wafer.
Two experiments were conducted:
- A filter of 100 nm was instilled in the pure water system to reduce the number of particles and reduce the number of defects on the wafer. A positive result was received. The number of defects on the wafer reduces. The explanation of the improved performance is as follows: 100nm filter stops particles and improves the purity of the water.
- A filter of 10nm was installed in addition to a 100nm filter for the pure water system. It was expected that the water purity would be additionally improved and the number of defects on the wafer would be reduced. Nevertheless, the number of defects on the wafer increased. Replacement of the wafer of 10nm for the finer filter of 3 nm did not result in better performance.
The main question is - why do fine filters unexpectedly result in an increased number of defects?
What is the model of failure?
What is the solution?
Similar projects
Semiconductor devices are becoming more complex and expensive. But what exactly are we paying for when we buy a computer, cellphone, or any device containing a microchip? It’s not for radically new functions—the core components remain the same: transistors and interconnections. According to Moore’s law, transistors are getting smaller, with more interconnection layers added, making the manufacturing process longer and more costly. In reality, we’re paying for the inability of engineers to efficiently solve engineering challenges. This project leverages System Functional Modeling (SFM) to analyze the IC interconnection layer and Process Functional Modeling (PFM) to evaluate its manufacturing process. These analyses aim to deepen our understanding of both the device and the production process, generating innovative solutions for cost reduction and improved efficiency.
Wet cleaning is widely used in microchip manufacturing. Single wafer equipment is working as follows. A wafer rotates, and chemistry is poured from a movable nozzle. Water rinsing is performed at the end of the process. Loading of a new batch of the chemistry resulted in excursion - a strongly increased amount of defects was observed on the wafer after the processing. The project is dedicated to the failure analysis and creation of innovative solutions.
The process is related to microelectronics - microchip manufacturing. The purpose of the process is to create a SiO2 layer on the surface of a Si wafer. Equipment: Vertical furnace to heat the wafers in the Q2 atmosphere and perform oxidation on the wafer surface. Process: The oxidation occurs on the front side and on the back side of the wafer Requirements: Create a SiO2 thin layer with a certain thickness and low sigma - low standard deviation of the thickness between the wafers and within the wafer Failure: Wafers from the lower zone have higher thickness and significantly higher within wafer sigma (standard deviation of the thickness within the wafer)