Process for low-k dielectric with dummy plugs

摘要

Low dielectric inter-metal dielectric (IMD) layers made of hydrogen silsesquioxane (HSQ) or methyl silsesquioxane (MSQ) spin-on-glass do not have good thermal conductivity as compared to regular oxides, in addition the adhesion of HSQ or MSQ is worse than that of oxide to oxide layers Methods are disclosed and illustrated to improve the heat transfer by providing metal dummy plugs under and/or around bonding pads or between metallization layers. The arrangement and numbers of dummy plugs depends on the heat to be transferred and varies with the application. Good thermal conductivity is of particular importance because the effects of high local temperature around bonding pads during chip bonding results in thermal stress and delamination of the IMD layers. The use of bonding pads provides other benefits as well.