A Contact Stud Process for VLSI Or ULSI
Original Publication Date: 1988-May-01
Included in the Prior Art Database: 2005-Feb-15
A process for forming contact windows and titanium studs to facilitate metal interconnections in an integrated circuit is disclosed. The method can be practiced according to the following steps: 1. Providing a semiconductor wafer having integrated circuit devices covered by a layer of borophosphosilicate glass (BPSG). 2. Depositing a layer of photoresist on the BPSG layer. 3. Lithographically defining a contact mask in the photoresist layer. 4. Vertically etching the contact windows through the BPSG with a CHF3/O2 gas mixture in a reactive ion etch chamber. 5. Etching the contact windows with a 50:1 buffered hydrofluoric acid solution. 6. Evaporating titanium in a conformal manner such that the contact windows are filled. 7.