A method for manufacturing an air bridge in a semiconductor process

Abstract

The invention discloses a manufacturing method of a semiconductor process air bridge. The manufacturing method has the advantages that a sacrificial layer and back electrode patterns are manufacturing by LOR-series photoresist and AZ52-series photoresist, different types LOR photoresist and different photoresist smearing rotation speeds can be selected according to the different heights of steps, and single-layer and double-layer photoresist smearing can be used flexibly; due to the fact that the LOR-series photoresist is a non-photosensitive material and the AZ52-series photoresist is a photosensitive material, a line width structure is decided by the upper-layer AZ52-series photoresist, and the high-resolution and high-photosensitivity upper-layer AZ52-series photoresist can be applied to the high-step and small-line-width device structure.

Description

technical field [0001] The invention relates to the technical field of air bridge preparation, in particular to a preparation method of a semiconductor process air bridge. Background technique [0002] In high frequency and ultra-high frequency devices, it is necessary to reduce the parasitic capacitance of metal electrode leads to improve the sensitivity of the device. Since the dielectric constant value of air is close to 1, using the air bridge method to realize the metal electrode leads can greatly reduce the parasitic capacitance and avoid the use of the process of depositing expensive low dielectric constant dielectric film materials; at the same time, the air bridge structure provides the electrode leads. Low thermal resistance connections and heat dissipation channels. [0003] At present, positive photoresists such as AZ series and S18 series are widely used in the existing technology as the sacrificial layer of the air bridge process, or a metal layer is evaporate...

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Problems solved by technology

[0003] At present, the existing technology generally uses positive photoresists such as AZ series and S18 series as the sacrificial layer of the air bridge process, or evaporates a metal layer on the sacrificial layer as a seed layer to protect the sacrificial layer; Metal electrode patterns usually use a single-layer thick positive photoresist or multi-layer positive photoresist as the mask layer; (1) use positive photoresist as the sacrificial layer of the air bridge process, and the positive photoresist The high temperature resistance is limited. When the temperature is too high during high temperature baking, it will cause carbonization, which will cause the sacrificial layer to be removed. During the electrode pattern exposure step, the sacrificial layer will be exposed to light and be eroded by the developer, causing the surface of the air bridge metal lead to be uneven. If a layer of metal is evaporated on the sacrificial layer as a seed layer to protect the sacrificial layer, the process cost will be increased. And later, it is necessary to remove the seed layer by etching, which makes the process more complicated; (2) use positive photoresist as the sacrificial layer on the high-step substrate and the photoresist mask layer when making electrode patterns later, and the step Too high determines that a thicker positive photoresist must be used, and the resolution of thick positive photoresist is relatively low, so this method cannot be applied to devices with high steps and small line widths (such as line width pattern structures below 2um)

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