Metallization Compatible With Metal RIE Over Partially-Covered Contacts
Original Publication Date: 1988-Jan-01
Included in the Prior Art Database: 2005-Feb-14
A process is described which facilitates the patterning of an aluminum- based metallization over partially covered contact areas without etching/damaging the underlying silicon substrate. A partially-covered contact occurs when a wiring layer of an integrated circuit runs through an opening to a prior level, leaving a portion of the prior level exposed, as shown in Fig. 1. The use of partially-covered contacts in integrated circuit designs allows higher wiring densities than can be achieved in the fully-covered case (not shown). Subtractive etching methods used for wiring level patterning may attack these exposed areas. This is the case for an aluminum-based metallization with partially-covered contacts. The underlying silicon is exposed to an RIE.