A polysilicon stress sensor and its manufacturing method

Abstract

The invention provides a polysilicon stress sensor and a making method thereof. The polysilicon stress sensor at least includes: a silicon substrate; a silicon pore structure formed in the silicon substrate; a first barrier layer, which covers the front surface of the silicon substrate and the upper side wall of the silicon pore structure; a polysilicon layer, which is formed on the first barrier layer surface, and the lower side wall and bottom of the silicon pore structure; a second barrier layer, which covers the polysilicon layer surface; and an electrode structure, which includes a first electrode for leading out the polysilicon layer and a second electrode for leading out the silicon substrate. According to the invention, a polysilicon force sensing resistor is made on the side wall of a blind hole or through-hole, and by means of the connection effect of the substrate silicon, making of two end leads of the force sensing resistor and a bonding pad on a silicon chip front side can be achieved. At the same time, as the axial force sensitivity of a polysilicon resistor in the hole is far larger than the radial sensitivity, the sensor provided by the invention can be used for measuring the internal axial stress introduced during electroplating copper filling of blind hole and through-hole heat treatment.

Description

technical field [0001] The invention belongs to the technical field of integrated circuit manufacturing, packaging and measurement, and in particular relates to a polysilicon stress sensor and a manufacturing method thereof. Background technique [0002] With the development of three-dimensional packaging and three-dimensional chip stacking technology, Through Silicon Via (TSV) technology has become one of the advanced technologies in the integrated circuit industry. Compared with traditional two-dimensional integration, TSV interconnect technology provides vertical and shorter-distance connections, reduces the distance of information circulation, and improves packaging integration. TSV interconnection has won more and more attention and has been widely used in radio frequency systems, imaging sensors, high-speed logic memory chips, multi-core processors, etc. [0003] Since the TSV structure is a Cu-Si composite structure filled with electroplated copper, the structure has...

AI Technical Summary

Problems solved by technology

At present, the research on the thermal stress distribution inside the TSV structure is mainly through finite element analysis software simulation and section analysis. The finite element analysis is to calculate the through hole by setting the performance parameters of the materials of each layer of the TSV structure in the software and dividing the grid. The stress distribution in each direction is often different from the actual stress distribution, and the cross-section analysis is to measure the stress of the heat treatment process with the test equipment after cutting along the TSV cross-section, which itself causes damage to the TSV, and the analysis of the TSV cross-section structure It does not reflect the thermal stress of the complete TSV structure

There are also reports in the literature that micro-Raman spectrometers are used to analyze the thermal stress distribution on the surface of TSVs. As we all know, the stress of the through-hole structure is mainly concentrated inside the through-holes, and most of the thermal stress on the surface is often released. Only the thermal stress on the surface is analyzed. stress is never enough

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