Fabrication method of stress-matched bi-material micro-cantilever beam

Abstract

The invention discloses a manufacturing method for a stress-matching bimaterial microcantilever. The method comprises the steps of deposing a pressure stress SiO2 film with a stress of F1 on a substrate by using LPCVD, wherein F1 is smaller than 0; injecting a dopant into the pressure stress SiO2 film; annealing a heavy doped SiO2 film on the surface of the pressure stress SiO2 film so as to make the pressure stress SiO2 film transferred into a tensile stress SiO2 film with a stress of F2, wherein F2 is larger than 0; and forming an Al film with a stress of F3 on the heavy doped SiO2 film by controlling a deposition temperature, wherein F3 is equal to F2. According to the manufacturing method for the stress-matching bimaterial microcantilever, the process is simple and is compatible with a conventional micro-machining process, complete stress matching of the bimaterial microcantilever is realized, resistance to XeF2 corrosion of the SiO2 is obviously enhanced, and finally the manufacture of the cantilever with bimaterials of Al and SiO2 and complete stress matching is successfully realized.

Description

technical field [0001] The invention relates to a method for manufacturing a semiconductor device, in particular to a method for manufacturing a stress-matched double-material micro-cantilever beam. Background technique [0002] With the rapid development of vacuum science technology, optoelectronic technology and semiconductor technology, thin-film optical devices and thin-film electronic devices have been widely used. In the optical readout uncooled infrared focal plane imaging system based on the micro-cantilever array structure of MEMS, its core structure is the uncooled infrared detector system, that is, the dual-material micro-cantilever infrared focal plane array (FPA), which consists of a series of The imaging pixels form an areal array, and each pixel is composed of two materials with very different thermal expansions. The pixel converts the radiation energy into heat energy by absorbing the infrared radiation of the object, and converts the heat energy into the ro...

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Problems solved by technology

[0006] Although, the tensile stress LPCVDSiO can be achieved by impurity implantation process and annealing process 2 film preparation, but due to LPCVDSiO 2 The differences in film deposition equipment, growth conditions and film thickness, the prepared LPCVDSiO 2 After the impurity implantation process and annealing process of the film, the tensile stress LPCVDSiO formed 2 The stress value of the film has a large range of variation, and its value is 0MPa to 200MPa, which cannot achieve the same stress of the Al film as that of LPCVDSiO 2 Complete matching of the film stress, and the existing process cannot make the Al film stress also continuously adjust from negative stress to positive stress

[0007] In summary, prior art SiO 2 The thin film preparation process cannot take into account the perfect stress matching and corrosion resistance, and cannot be effectively used in the preparation process of the dual-material micro-cantilever infrared focal plane array

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