Applied Materials has declared its Vantage Vulcan rapid thermal processing system, which is used to heat silicon wafers from the rear for enhanced control and production efficiency.
Applied Vantage Vulcan™ rapid thermal processing (RTP) system
According to the VP for Applied Materials’ Front End Products, Silicon Systems Group, Sundar Ramamurthy, rapid thermal processing (RTP) involves the heating of silicon wafers to ultra-high temperatures in a few seconds termed as a spike anneal process that improves transistor performance. Ramamurthy mentioned that one of the vital factors of the process is the repeatability of peak temperature. This process allows users to reach this temperature repeatedly for every single wafer and ensures that it has the accurate profile.
For chip producers, transistors with the same design should render the same level of performance across all areas of the wafer to increase yield. At 28nm and below, transistors are small and more responsive to temperature fluctuations and since many logic chips are large; it becomes a challenge to achieve uniformity across the die.
In addition, materials usually used on wafers for achieving various features respond differently to heat. Direct radiant heating from conventional front side RTP may result in temperature fluctuations, or hot spots on a wafer pattern, which contributes to major changes in the transistor’s electrical performance causing several low-end chips on the wafer.
According to Applied Materials, during RTP its Vantage Vulcan system applies heat to the unpatterned rear of the wafer, resulting in evenness of temperature across the wafer. The company’s honeycomb lamp array can be used with the system to maintain within-die temperature to 3°C or below even when the temperature of the wafer is increasing above 200°C per second. The Vantage Vulcan system has a special closed-loop control to keep a check on wafer temperature dynamically from room temperature to 1,300°C.