Plasma resistance vs Purity - can you have both?

Throughout the whole semiconductor manufacturing process flow, particle contamination is a significant threat to yield and profitability.  Vacuum processes such as dry etch and deposition, require elastomer seals to maintain vacuum integrity while being in direct contact with aggressive process chemistries.  Plasma erosion of the seal over time is inevitable but it should not contribute to yield loss through whatever by-products may be formed.

The choice of seal materials available is vast, so how do you choose the right material?

Should you spend time and resources testing, or the risky option of installing a new seal material in live production?

A comprehensive study has been carried out to benchmark a number of seal materials from the leading elastomer O-ring suppliers.  Materials were evaluated for their relative erosion rates or, mass loss and observation of surface particle formation. TGA spectra were also carried out in order to determine the nature of the material compound and in particular whether the material was purely organic and filler free, contained organic filler or, contained inorganic filler. The process chemistries were:

• O2 in a direct parallel plate plasma system
• O2 in a remote ICP system
• Cl2, BCl3, HBr in a remote ICP system
• SF6, O2 in a remote ICP system
• SF6 in a low volume ICP optimized high radical plasma system

The fillers used in elastomer compounding play an important role in plasma resistance. Most organic polymers have higher etch rates than the fillers. In order to achieve optimum etch resistance, organic polymers are usually compounded with various types of fillers.  When the polymer matrix is etched away, the filler particles become free and can cause contamination and therefore reduce product yields.  Plasma resistance and purity, can you have both?

Download the whitepaper to find out how the elastomer materials performed >>>