Al-Reflow Process with a “Cap-Clamp” for Sub-Micron Contact Holes

Publisher Website
Google Scholar
Abstract
The use of “cap-clamp” has been demonstrated for extending the process margin of Al-reflow process. To evaluate the process window of Al-reflow with and without the “cap-clamp”, two major factors of in-situ annealing temperature and time were varied between 500-560° C and 40-90 seconds, respectively. Sub-micron contact holes were completely filled by heating wafers at 500° C or higher temperatures by adopting the “cap-clamp” to the conventional conduction heating system. The effect of the “cap-clamp” comes from the improved heating efficiency of the wafer by introducing hot Ar gas into the inner space of “cap-clamp”, resulting in faster ramp-up as well as more effective heating of the front-side of the wafer. Al-reflow with the “cap-clamp” gives wider process window than that of the conventional heating method and realizes the contact planarization of 256 Mbit dynamic random access memory (DRAM) and beyond.

This publication has 0 references indexed in Scilit: