Scalable Particle Removal for sub-5 nm Nodes

Abstract

Wet cleaning has become challenging as the feature size of semiconductor devices decreased to sub-5 nm nodes. One of the key challenges is removing various types and sizes of particles and contamination from complex and fragile 3D structures without pattern damage and film loss. Conventional physical cleaning methods, such as dual-fluid spray or megasonic cleaning, are being used for the particle removal process. However, in advanced device nodes, these methods induce pattern damage and film loss. In this paper, we describe a novel particle removal technology called Nanolift which uses a polymer film consisting of two organic resins with different functions and achieved high particle removal efficiency on various types and sizes of particles with no pattern damage and minimum film loss.

Evaluation and Optimization of Particle Removal with a Resist Peeling Method

“…This explains the decrease in PRE data as the aging time increases. The PRE data for particles aged for 14 days reveals a correlation between cleaning effectiveness and particle size, which contradicts previous studies evaluating this process [5]. However, it should be noted that these results were obtained using a different contamination method, aging conditions, and aging time, making direct comparison irrelevant.…”

“…The resist film is made of two immiscible polymers with a different solubility in diluted ammonia. The idea is to form penetrating holes with the dissolution in ammonia of the minority polymer, enabling the film lift off [5]. The immiscibility between the two polymers leads to a specific spatial organization with circular cavities on the film surface, as shown in Figure 1.…”

“…Therefore, some common particle removal techniques are not relevant anymore in specific cases. This led to the development of new cleaning processes based on innovative concepts in recent years, such as resist film lift off [1,2,3,4,5]. The particle removal process developed by SCREEN Semiconductor Solutions Co. [5] is one of them.…”

“…This led to the development of new cleaning processes based on innovative concepts in recent years, such as resist film lift off [1,2,3,4,5]. The particle removal process developed by SCREEN Semiconductor Solutions Co. [5] is one of them. This specific resist film is made of two immiscible organic polymers.…”