Silicon bonding method

Abstract

The invention discloses a silicon wafer bonding method. The method comprises the following steps: providing a first silicon wafer, and forming an island structure in the first silicon wafer; forming a first oxide layer on the first silicon wafer with a thermal oxidation process, wherein the oxide layer is thicker than a central region on the edge of the island structure; forming a second oxide layer on the first oxide layer with a high-density plasma vapor deposition process, and performing rapid thermal annealing treatment, wherein the oxide layer is thinner than the central region on the edge of the island structure, and the first oxide layer and the second oxide layer are taken as bonding oxide layers; and providing a second silicon wafer, wherein the second silicon wafer is bonded with the first silicon wafer through the island structure. According to the characteristics of different processes, the thicknesses of the first oxide layer and the second oxide layer on the island structure compensate with each other, and high surface microcosmic flatness is achieved, so that a large bonding area is achieved when the first silicon wafer and the second silicon wafer are bonded together, and the bonding strength is enhanced.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a silicon wafer bonding method. Background technique [0002] In recent years, with the development of micro-electromechanical system (Micro-Electrico-Mechanical-System, MEMS) technology, various micro-electromechanical devices, including: micro-sensors, micro-actuators, etc., have achieved miniaturization, which is beneficial to Improve device integration, so MEMS has become one of the main development directions. [0003] Common fabrication methods for MEMS include bulk silicon fabrication processes, specifically involving the bonding of silicon wafers. Please refer below as Figure 1-5 The schematic diagram of the device structure in the silicon wafer bonding process shown in the prior art. [0004] Such as figure 1 As shown, first, a first silicon wafer 1 is provided, and a mask layer 2 is formed on the first silicon wafer 1 . Then, the mask layer 2 is patterned, ...

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Problems solved by technology

Obviously, such a bonding strength is very low, and it is easy to cause partial detachment or even complete detachment, which seriously affects the reliability of the device.

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