Silicon oxide etching method

Abstract

The invention relates to a silicon oxide etching method, and relates to the technical field of etching. The method can alleviate the etching load effect of silicon oxide. According to the embodiment of the invention, the method comprises the steps: carrying out the etching of the silicon oxide through etching gas which comprises octafluorocyclobutane gas and oxygen, wherein polymer generated by the octafluorocyclobutane gas in an etching process reacts with the oxygen to generate volatile gas.

Description

technical field [0001] The invention relates to the technical field of etching, in particular to a silicon dioxide etching method. Background technique [0002] In the field of optics, the optical waveguide technology that fabricates several optical passive devices on the same substrate and interconnects them to form functional circuits through waveguides is a very practical technology. Because silica optical waveguides have good optical, electrical, mechanical properties and thermal stability, and are low in cost, silica optical waveguides are widely used in the field of optical waveguide technology. [0003] figure 1 It is a partial cross-sectional schematic diagram of a silicon dioxide optical waveguide in the prior art, and the silicon dioxide optical waveguide has a narrow groove 1 and a wide groove 2 . Usually dry etching method is used to etch silicon dioxide to form a silicon dioxide optical waveguide with the above structure, for example, octafluorocyclobutane (ch...

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Problems solved by technology

During this etching process, C 4 f 8 The polymer generated by the chemical reaction is deposited at the bottom of the narrow groove 1. As the etching depth increases, the bombardment of the Ar plasma cannot completely remove the polymer deposited at the bottom of the narrow groove 1, resulting in an increase in the deposited polymer. Finally, the progress of the etching reaction is hindered, so that the etching of the narrow groove 1 is terminated, and the depth h1 of the narrow groove 1 is too small, so that the difference between the depth h1 of the narrow groove 1 and the depth h2 of the wide groove 2 is large, resulting in the oxidation of The etching loading effect of silicon is obvious, which affects the performance of silicon dioxide optical waveguide devices

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