Bridge-type thermal film microheater, preparation method, and electronic nose array

Abstract

The invention discloses a bridge-type thermal film microheater, a preparation method, and an electronic nose array. The bridge-type thermal film structure microheater comprises a heat insulating layerformed on a surface of a silicon substrate; an insulating layer I formed on the surface of the heat insulating layer; electrode poles formed on the surface of the insulating layer I; a cavity and suspended heating structure formed between the electrode poles, wherein the heating structure is sequentially provided with a support layer, an insulating layer, a step structure layer, a heating layer and a passivation layer in order from the cavity. The insulating layer covers the support layer, and the step structure layer is located on the insulating layer. The heating layer covers a composite structure including the support layer, the insulating layer and the step structure layer, and covers the upper surfaces of the electrode poles. The passivation layer covers the heating layer, and a connection electrode is located on the surface of the silicon substrate containing the heat insulating layer, and is connected with the electrode poles. The insulating layer I, the electrode poles and thesupport layer together form a cavity of the suspended heater structure.

Description

technical field [0001] The invention relates to the technical field of microelectronic devices and their preparation, in particular to a bridge-type thermal film structure micro heater, a preparation method and an electronic nose array. Background technique [0002] At present, the existing micro-heater preparation process mainly adopts the front or back bulk silicon etching process. The micro-heater prepared by this process has the disadvantages of large size, high power consumption, difficulty in arraying, high stress of sensitive film, poor heat insulation and unsatisfactory high temperature thermal stability. This restricts the development and application of micro-heating structure sensors such as micro-gas sensors, micro-calorimeters, micro-barometers, micro-accelerometers, and electronic noses. [0003] With the rapid development of modern microelectronics technology, micro-hotplates with small volume, low power consumption and easy combination with other materials or...

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Problems solved by technology

[0005] Through the above description process, it can be concluded that the traditional micro-heater preparation process has the following disadvantages: the size of the micro-heater prepared by the front bulk silicon process and the micro-heater prepared by the back bulk silicon process reach hundreds to thousands of microns , and the thermal insulation performance of the structure is not good, and it has a large power consumption; the micro-heater prepared by the traditional front / back bulk silicon etching process is likely to cause device failure due to the stress between the films during the preparation process, and it is impossible to achieve thermal insulation and thermal insulation at the same time. It has the advantages of high mechanical strength and high product yield; in the process of process preparation and packaging, the process of preparing the micro heater by the front bulk silicon etching technology is relatively difficult, and the micro heater prepared by the back bulk silicon etching method is difficult in the packaging process. The backside cavity structure is prone to loss, and both microheaters have the characteristics of low yield

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