VPC (Vapor Phase Cleaning) is studied to etch various types oxide film using a mixture of HF gas and H2O vapor. We focused on controlling the amount of gas molecules adsorbed on the oxide surface and investigated the H2O amount included in oxide films, which will contribute to the oxide etching reaction. We have verified that selective etching between different oxide films can be achieved by controlling the gas adhesion amount by varying process parameters and utilizing the different amounts of H2O in the oxide films for several deposition methods.

We investigated an alternative technology to conventional organic material removal that replaces sulfuric acid and hydrogen peroxide (SPM). We assumed that the removal model of organic material by ozone gas was absorption of oxygen radicals, generated by thermal decomposition of ozone, on a surface and subsequent reaction with organic materials. Then we characterized the correlation between removal rate and process parameter, and the validity of the model was verified. It also showed that this method is effective for high dose, ion-implanted photoresists.

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.

Thermally activated ozone gas (TAO) was demonstrated as an alternative technology to conventional spin-on carbon (SOC) stripping. The SOC stripping rate with ozone gas was found to be a function of substrate temperature and actual ozone amount calculated from the ozone flow rate and concentration. Furthermore, work function metal (WFM) stripping rate showed a high selectivity to SOC films, and the amount of oxidation TiN, which is a WFM metal, was also equivalent to conventional technology of SOC stripping. This TAO gas process can be used in clean tools, making it a promising integrated solution for SOC stripping followed by post clean.