Method for forming inter-metal dielectric and structure of inter-metal dielectric

Abstract

The invention relates to a forming method of a metal inter-lamination dielectric layer and further relates to the metal inter-lamination dielectric layer. The forming method of the metal inter-lamination dielectric layer comprises the following steps: step A, a silicon rich oxide is deposited on a metal layer of a wafer to form a silicon rich oxidation layer; step B, silicon glass with fluoride doped is deposited on the silicon rich oxidation layer to form a fluoride-doped silicon glass layer; step C, silicon glass which is of non-fluoride-doped is deposited on the fluoride-doped silicon glass layer to form a non- fluoride-doped silicon glass layer; and step D, the non-fluoride-doped silicon glass layer is formed by one side of the non-doped silicon glass layer and chemical mechanical lapping is conducted on the one side of the non-doped silicon glass layer. The fluoride-doped silicon glass is filled on the bottom of IMD (Inter-metal dielectric) and is good in filling performance, and meanwhile, non- fluoride-doped silicon glass is used as a blocking layer of the fluoride-doped silicon glass layer to prevent the fluoride from spreading. Filling quality is guaranteed, and meanwhile, required processes are less, cost is saved, and work efficiency is improved.

Description

【Technical field】 [0001] The invention relates to the field of semiconductor manufacturing, in particular to a method for forming a metal interlayer dielectric, and also to a metal interlayer dielectric structure. 【Background technique】 [0002] With the development of integrated circuit technology, the size of integrated circuits is also continuously reduced according to Moore's law, which requires continuous new technology to support the ever-increasing product requirements, especially for the requirements of the back-end process line width. is strict. For the deposition and manufacturing of the existing inter-metal dielectric (IMD), the aluminum (AL) process technology is used to fill structures with a large aspect ratio. Require. [0003] In the industry's traditional back-end process of aluminum wires, the following two processes are generally used for filling structures with large height-to-width ratios: [0004] 1. Deposition of silicon-rich oxide (SRO) + high-dens...

AI Technical Summary

Problems solved by technology

For the first process, the filling aspect ratio (ie figure 1 In the structure where h / w) is greater than 2, obvious voids are prone to appear. In this way, in the subsequent manufacturing process of metal vias (VIAtoMetal), it is easy to cause tungsten plugs to enter the voids, resulting in metal bridges. ) or cause other reliability issues

[0007] In the second process, fluorine-doped silicon glass is deposited, so it needs to be covered with a layer of orthosilicate to prevent the fluorine from diffusing out (diffuseout) and crystallization to form bubbles, which leads to more steps in the process and increases the cost. and reduced production efficiency

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