Etching method

A technology for etching gas and grooves, which is applied in the direction of electrical components, semiconductor/solid-state device manufacturing, circuits, etc., can solve the problems of limited passivation effect, short gas introduction time, etc., to reduce the lateral etching speed and reduce side effects. Wall bending phenomenon, the effect of improving product quality

CN105097494BActive Publication Date: 2018-03-06BEIJING NAURA MICROELECTRONICS EQUIP CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2018-03-06

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Abstract

The present invention provides a kind of etching method, and this etching method comprises the following steps of carrying out alternately: Initial deposition step, pass into deposition gas, form the first protective layer on the bottom wall surface and the side wall surface of the groove of substrate In the initial etching step, an etching gas is introduced to etch the first protective layer on the bottom wall surface of the groove, and a protective gas is introduced at the same time, and the protective gas can oxidize the substrate to form a A second protection layer is formed on the bottom wall surface of the trench and on the first protection layer on the side wall surfaces. In the present invention, the etching method can form the first protective layer and the second protective layer on the sidewall surface of the trench. Compared with the prior art, the etching method provided by the present invention can reduce the lateral etching speed , so that the occurrence of side wall bending can be effectively reduced, thereby improving product quality.
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Description

technical field

[0001] The present invention relates to the field of semiconductor manufacturing, in particular to an etching method. Background technique

[0002] With the breakthrough and rapid development of high aspect ratio anisotropic etching technology, more and more microelectromechanical systems (MEMS) devices are developing towards high aspect ratio structures. To achieve the high aspect ratio goal, dry etching is usually used. However, in the early stage of deep silicon etching, due to insufficient protection of the top of the silicon groove, line width loss or bowing of the side wall is often caused. As the reaction progresses, the etching depth continues to increase, and the transport of reactants and products is uniform Being hindered, a considerable part of the ions are attracted to the sidewall due to the action of the electric field in the narrow groove space, resulting in a decrease in the longitudinal etching rate and resulting in shrinkage of the bottom....

Examples

specific Embodiment approach

[0040] As a specific embodiment of the present invention, the temperature in the etching method is 20°C±1°C, and the process parameters in the initial deposition step are: the pressure in the process chamber is 15mT-70mT; 1000W-2000W to ionize the deposition gas into plasma; the flow rate of the deposition gas is 120sccm-200sccm; the deposition time is 2s-6s.

[0041] In the present invention, the initial etching step may include etching the first protective layer 1 on the bottom wall surface of the trench, and when the first protective layer 1 is etched away, continue to etch the first protective layer 1 underlying substrate material. That is, the initial etching step may include:

[0042] S101. Adjust the power of the upper radio frequency power supply and the lower radio frequency power supply, and inject the etching gas to etch away the first protective layer 1 formed on the bottom wall surface of the trench, exposing the material of the substrate;

[0043]S102. Adjust t...