Method for measuring inclination of opening and preparation method of three-dimensional memory

Abstract

The invention discloses a method for measuring the inclination of an opening, an etching detection method for a three-dimensional memory channel through hole and a preparation method of the three-dimensional memory. The measuring method comprises the steps of: measuring an appearance of an opening from a top direction of the opening by using an electron microscope; acquiring a top contour image ofthe opening; adjusting an image processing algorithm function of the electron microscope, and using a top detector of the electron microscope to obtain a bottom contour image of the opening; performing data processing, and calculating a top center-of-gravity position and a bottom center-of-gravity position of the opening; and determining the inclination of the opening according to the top center-of-gravity position and the bottom center-of-gravity position of the opening, wherein the inclination comprises the inclination angle of the opening in the axial direction and the inclination angle ofthe opening of the opening bottom contour relative to the top contour, the depth of the opening is larger than or equal to 4[Mu]m, and the electron microscope is a high voltage scanning electron microscope.

Description

technical field [0001] The invention relates to the field of semiconductor preparation technology, in particular to a method for measuring the inclination of an opening, an etching detection method for a channel through hole of a three-dimensional memory, and a method for preparing a three-dimensional memory. Background technique [0002] Memory is a memory device used to save information in modern information technology. In order to obtain higher integration and data storage density, the critical size of the memory needs to be continuously reduced, and the corresponding process cost and technical requirements are continuously improved; in this case, the ordinary planar memory cannot meet the actual mass production needs gradually. Three-dimensional (3D) memory came into being. In a three-dimensional memory, a channel hole (Channel Hole, CH) is an important channel for carrier movement, and the stability of its formation process has a very important impact on the product yi...

AI Technical Summary

Problems solved by technology

However, studies have found that in the preparation process, the opening of the hard mask layer often has a misalignment between the bottom and the top, that is, the hard mask opening (HMO) is tilted (Tilting); if such a hard mask layer is used Executing the etching process will directly affect the formation of channel vias, resulting in channel vias that cannot meet design requirements

Furthermore, the etching failure of the channel through hole will have an adverse effect on the subsequent process, such as causing problems such as opening dislocations in the etching of the stacked film (such as SONO) in the subsequent channel via hole, and in severe cases, it will cause the stacked film layer. The polysilicon layer is damaged or even the oxide layer is damaged, so that the channel layer cannot be turned on, and the resulting three-dimensional memory fails

Images