Slot filling method in multilayer integrated circuit

Abstract

The invention discloses a slot filling method in a multilayer integrated circuit. In the method, slots are etched on the surface of a silicone wafer, and a layer of silicon dioxide is grown by thermal oxidation, and then the following steps are carried out: firstly, depositing a layer of silicon dioxide on the surface of the silicon wafer with the slots, wherein the layer of the silicon dioxide is a laying layer; secondly, depositing a layer of silicon dioxide mixed with p type or n type impurities on the laying layer, wherein the silicon dioxide mixed with the impurities fills the slots and is the material of the interlayer media of the first layer; and thirdly, carrying out planarization treatment on the silicon dioxide on the surface of the silicon wafer by a chemical mechanical polishing process until the required thickness of the interlayer media of the first layer is met. In the invention, the filling of the slots and the preparation of ILD-1 are skillfully integrated, and the material of the ILD-1 is determined as the silicon dioxide mixed with the impurities simultaneously. The silicon dioxide mixed with the impurities has good fluidity, and therefore, the requirements for filling deep slots with different widths can be completely met.

Description

technical field [0001] The invention relates to a manufacturing process of a semiconductor integrated circuit. Background technique [0002] Modern semiconductor integrated circuits adopt a multi-layer structure (at least two layers), with silicon at the bottom, one or more layers of metal on top of the silicon, and interlayer dielectrics between each layer of metal and between the first layer of metal and silicon. (ILD). [0003] In the underlying silicon manufacturing process, it is often necessary to fill the trenches with an isolation dielectric (such as silicon dioxide). The Shallow Trench Isolation (STI) process is a common trench filling method, but it is only suitable for shallow trenches (depth below 1 μm). For deep trenches (with a depth between 1 μm and 10 μm), multiple filling methods are usually used, and the specific steps are as follows: [0004] At the beginning, the surface of the silicon wafer has just etched a groove 10, and a layer of silicon dioxide (...

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