Surface Planarization Technique
Original Publication Date: 1980-May-01
Included in the Prior Art Database: 2005-Feb-13
A serious problem with microcircuit fabrication schemes that require after each lithographic step. This problem is illustrated in Fig. 1 for 5, a two-level magnetic bubble device. The conductors 10 are delineated with the first masking level and are then covered by a sputtered SiO(2) layer 12. Layer 12 serves as an insulator and spacer between conductors 10 and the second level of metallization, the permalloy propagation elements (not shown). When the proper thickness of SiO(2) has been attained, the resulting surface is nonplanar. Therefore, step coverage by the permalloy elements becomes difficult and magnetic effects may be introduced because the shape of these elements will deviate from the desired rectangular geometry.