A method of planarizing integrated circuit devices which is compatible with VLSI requirements is presented. This method utilizes either cw or pulsed radiation from a tunable CO2 laser to selectively heat, for example, a thin layer of phosphosilicate glass causing it to flow. Flow, which is characterized as a decrease in glass viscosity sufficient to provide smoothing of the device topography, occurs without adversely affecting the under-lying or exposed device materials. Application of the laser activated flow method to the fabrication of integrated circuits with multilevel metallization systems is demonstrated.
M. Delfino, M. Delfino,
"Laser Activated Flow For Integrated Circuit Fabrication", Proc. SPIE 0385, Laser Processing of Semiconductor Devices, (9 August 1983); doi: 10.1117/12.934945; https://doi.org/10.1117/12.934945