A Method for Improving the Uniformity of Gate Oxide Thickness

Abstract

The invention provides a method for improving the uniformity of grid oxide thickness. The method is carried out in a quartz tube device, comprising the steps of: introducing a certain flow ratio of deuterium gas and oxygen into the quartz tube, and igniting the deuterium gas React with oxygen to generate D2O, which neutralizes with Si-O-dangling bonds on the wall of the quartz tube to form Si-O-D, thereby avoiding the Si-O-dangling bonds on the wall of the quartz tube from affecting the growth of gate oxide Uniformity of thickness. According to the present invention, the deuterium D2 passed into the quartz tube and the D2O generated by the ignition reaction of oxygen can effectively neutralize the Si-O dangling bonds on the wall of the quartz tube to form a Si-O-D structure. Since the chemical reaction rate of deuterium is lower than that of isotopic hydrogen, the formed Si‑O‑D structure can exist stably in the quartz tube. In the DCE oxidation process of the subsequent gate process, it can avoid breaking the chemical balance of HCl, thereby reducing the activation of Cl-, and making the thickness of the gate oxide generated in the gate oxide oxidation process more uniform.

Description

technical field [0001] The invention relates to the technical field of semiconductor technology, in particular to a method for improving the uniformity of gate oxide thickness. Background technique [0002] At present, there are two processing techniques for quartz tube materials commonly used in the semiconductor industry: one is fused quartz. During the continuous melting process, quartz sand slowly enters the crucible from the top, and the outside of the crucible is equipped with electric heating elements. surrounded. The molten silica flows out from the forming port at the bottom of the furnace, and is controlled by the pull-down speed according to the required specification of the tube rod. Typical fused silica tube materials are GE214, GE224, HSQ300, HSQ330. The other is fumed quartz. The quartz sand is sprayed onto the quartz substrate in the holding furnace through the hydrogen / oxygen burner. The quartz substrate continues to rotate and slowly descends. The continu...

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Problems solved by technology

[0010] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a method for improving the uniformity of the gate oxide thickness, which is used to solve the problem of the gate oxide edge thickness grown in the gate oxide process caused by the low hydroxyl content of the quartz tube in the prior art. Thick problem

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