Contact Holes in Reflowable Glasses Reduced in Size With a CVD Sleeve
Original Publication Date: 1988-Sep-01
Included in the Prior Art Database: 2005-Feb-15
A process is reported for reducing the size of contact holes in borophosphosilicate glass (BPSG) beyond the photo limits to increase circuit density while also preventing a reflow of BPSG into the contact hole during a heat cycle used to activate an implanted species at the bottom of the hole. Small semiconductor geometries have caused increased use of glasses such as BPSG, which have desirable reflow characteristics that are used in replanarizing the passivating insulator. During a heat treatment cycle required to activate implanted impurities at the bottom of a contact hole, the BPSG reflows and may deform or close off the hole opening.