Foundry TOX grown 87% faster with New RASIRC Process
1000Å thick films on 300mm silicon wafer within 1.5% StdDev
Joint development between WRS Materials and RASIRC produced improved thermal oxide uniformity on 300 mm wafers while reducing the thermal oxide step from 100 minutes to 13 minutes.Tests recently confirmed a breakthrough in oxide film growth. 1000 Å films can now be grown on 300 mm wafers 87% faster than previously done with dry oxide. The new process involves a high flow rate of steam and oxygen. Uniformity was proven to be within 1.5% standard deviation. The faster process will allow manufacturers to increase production without adding new furnace tubes.
The new process overcomes serious technical challenges. To prevent uniformity issues, the process chamber is rapidly saturated with steam and oxygen. The steam is ultra-high purity, eliminating microdroplets. The oxygen is heated, avoiding condensation when the gases are blended.
Other devices commonly used to generate steam flow are inadequate for this application. Bubblers deliver only 15 slm and entrain droplets that cause non-uniformity. Torches operate at extremely high temperatures and consume volatile gases. As a result, torches have high costs, safety risks and special facility requirements.
The two companies have collaborated on a paper that details test protocols, results and provides guidelines for flow rate, thermal oxide thickness, and uniformity to optimize process recipe and reduce the time needed to achieve uniformity relative to gas flow rate.
Following the results of the joint development with WRS Materials, RASIRC commercialized the Steamer Turbo. RASIRC Steamer Turbo meets high flow requirements, saturating 400 mm furnaces in less than 2 minutes.
This device delivers ultra high purity steam blended with oxygen for high flow rate applications. The Steamer Turbo is able to deliver up to 100 slm of high temperature compressed gas with 50 slm of steam repeatable to ±1%