Effects of CH2F2 and H2 flow rates on process window for infinite etch selectivity of silicon nitride to ArF PR in dual-frequency CH2F2/H2/Ar capacitively coupled plasmas
| Autor: | N.-E. Lee, Han-Goo Kim, Hyung-Soo Mok, C. K. Park, Chang-Hyoung Lee |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Plasma etching
Hydrogen Analytical chemistry chemistry.chemical_element Photoresist Condensed Matter Physics Atomic and Molecular Physics and Optics Surfaces Coatings and Films Electronic Optical and Magnetic Materials Volumetric flow rate law.invention chemistry.chemical_compound Silicon nitride chemistry law Etching (microfabrication) Wafer Electrical and Electronic Engineering Photolithography |
| Zdroj: | Microelectronic Engineering. 85:375-387 |
| ISSN: | 0167-9317 |
| DOI: | 10.1016/j.mee.2007.07.012 |
| Popis: | The process window for the infinite etch selectivity of silicon nitride (Si"3N"4) layers to ArF photoresist (PR) and ArF PR deformation were investigated in a CH"2F"2/H"2/Ar dual-frequency superimposed capacitive coupled plasma (DFS-CCP) by varying the process parameters, such as the low frequency power (P"L"F), CH"2F"2 flow rate, and H"2 flow rate. It was found that infinitely high etch selectivities of the Si"3N"4 layers to the the ArF PR on both the blanket and patterned wafers could be obtained for certain gas flow conditions. The H"2 and CH"2F"2 flow rates were found to play a critical role in determining the process window for infinite Si"3N"4/ArF PR etch selectivity, due to the change in the degree of polymerization. The preferential chemical reaction of hydrogen with the carbon in the hydrofluorocarbon (CH"xF"y) layer and the nitrogen on the Si"3N"4 surface, leading to the formation of HCN etch by-products, results in a thinner steady-state hydrofluorocarbon layer and, in turn, in continuous Si"3N"4 etching, due to enhanced SiF"4 formation, while the hydrofluorocarbon layer is deposited on the ArF photoresist surface. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect