A highly manufacturable, low-thermal budget, void and seam free pre-metal-dielectric process using new SOG for beyond 60nm DRAM and other devices

Abstract

New PMD (Pre-Metal Dielectric) process by employing polysilazane based inorganic SOG (spin-on-glass) is suggested for future VLSI devices. Compared with conventional SOG materials, the film made from new SOG has higher wet etch resistance, which is critical in achieving deformation-free contact profile. Additional advantages of using this new SOG process are excellent gap-fill capability upto an aspect ratio (A/R) of 20 and lower thermal budget than BPSG reflow process. Neither detrimental effect of new SOG PMD process on electrical characteristics nor device performance such as refresh characteristic, compared to HDPCVD SiO/sub 2/ was observed, indicating this is a PMD process of choice for the future devices.