E-Beam Registration Mark Enhancement By Pyrocatechol Etch
Original Publication Date: 1982-Feb-01
Included in the Prior Art Database: 2005-Feb-08
Various registration schemes are successful for E-beam fabrication of devices. It is desirable to have deep marks which can withstand all processing steps. A method for forming deep registration marks at the first lithography level is as follows: 1. After the 10 micrometers wide registration mark pattern is defined in 1 micrometers of resist 1, the pattern is transferred through a 1000 angstroms of chemical vapor deposition (CVD) SiO(2)/400 angstroms of CVD silicon nitride, and 400 angstroms of CVD silicon oxynitride mask 2 by CF(4)/H(2) reactive ion etch (RIE). 2. The silicon substrate 3 is then etched to a depth of about 3800 A by CBrF(3)/O(2) RIE or similar etch to produce the Fig. 1 structure. 3.