Production method of deep groove isolation structure

Abstract

The invention discloses a production method of a deep groove isolation structure. After an epitaxial layer is grown, the method produces the deep groove isolation structure in the following steps: 1) growing silicon dioxide and silicon nitride in a furnace tube, and depositing silicon dioxide on silicon nitride; 2) performing exposure and development, and opening an area where a deep groove is to be etched in a dry etching mode; 3) utilizing silicon dioxide-silicon nitride-silicon dioxide formed by the step 1) to serve as an etching blocking layer, and forming the deep groove in the dry etching mode; 4) performing furnace pipe oxidation again, growing silicon dioxide, and fully oxidizing silicon below silicon nitride of a deep groove isolation area; 5) depositing silicon dioxide and sealing an opening of the deep groove; and 6) carrying out planarization of the surface of the deep groove. The method forms an ultra-thick field oxidation isolation layer by means of a deep groove etching and oxidation technology, and utilizes silicon nitride to serve as the blocking layer of planarization, thereby not only achieving isolation effect, but also greatly improving evenness in the surface and reducing difficulty of rear-end process.

Description

technical field [0001] The invention relates to the field of manufacturing semiconductor integrated circuits, in particular to a method for manufacturing a deep trench isolation structure. Background technique [0002] RF LDMOS power devices due to good electrical characteristics (for example, high linearity, high gain, high output power, high thermal stability, high operating voltage, simple bias circuit, constant input impedance, etc.) and compatibility with existing CMOS integrated circuit technology Good compatibility, has been widely used in the field of wireless communication. [0003] Traditional LDMOS devices generally use ordinary STI (deep trench isolation) and thick oxygen isolation. This isolation technology will cause problems such as poor in-plane uniformity and easy to cause liquid residue, which limits the application of RF LDMOS devices to a certain extent. Applications on high-speed high-frequency devices. Contents of the invention [0004] The technica...

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Problems solved by technology

[0003] Traditional LDMOS devices generally use ordinary STI (deep trench isolation) and thick oxygen isolation. This isolation technology will cause problems such as poor in-plane uniformity and easy to cause liquid residue, which limits the application of RF LDMOS devices to a certain extent. Application on high-speed and high-frequency devices

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