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新闻中心 Semiconductor IC Manufacturing> High purity HFC-41 Methyl Fluoride as a dry etching gas for Spacer etching

High purity HFC-41 Methyl Fluoride as a dry etching gas for Spacer etching

2019-05-24 14:06

As one of the manufacturers of fluorine-containing chemicals, Yuji Tech has the production and purification technology of HFC-41, whose purity can arrive Grade 4N(99.99%).

Methyl Fluoride (CH3F) , also known as Fluoromethane, Freon 41, Halocarbon-41 and HFC-41, is a non-toxic, liquefied and flammable gas at standard temperature and pressure. It is an environmentally friendly dry etching gas with low GWP, which shows very high performance in plasma etching of silicon compound films in semiconductor manufacturing.The physical properties, package and shipping are as follows.

Physical Data

Molecular Weight 34.03
Boiling point (℃) -78.4
Vapor pressure (bar, @0 ℃) 19.65
Critical temperature (℃) 44.5
Relative gas density (air = 1) 1.2
Gas Density (@15 °C, 1 atm, kg/m3) 2.18
Relative liquid density (water = 1) 0.61
Explosion limits (%vol) 2.6-21.7

Applications

Used as a composition in a mixture with other nonflammable refrigerant

Used as a dry etching gas in silicon-based integrated circuits

As a dry etching gas for Spacer etching

Time variation in the total positive ion flux in CH3F-O2-He plasma pulsed at 1 kHz for 75%, 50%, 20% and 10% dcs and continuous excitation (CW).[1]

1.A dielectric spacer, usually made of Si3N4, is also necessary around the gate to precisely define the channel length below the gate.

  1. Processes for spacer etching “are one of the most critical steps of transistor fabrication technologies.
  2. Silicon active layer is only 5-10nm thick, in order to ensure a high surface quality for the subsequent step of silicon epitaxy. Etching of the Si3N4 spacer can be achieved in CH3F-O2-He mixtures, which offer a high selectivity towards silicon.[1]

 

Reference:[1]https://www.sciencedirect.com/science/article/pii/S1631074818300389