Analysis method of semiconductor characteristics for preventing tungsten plug corrosion

Abstract

The invention discloses a semiconductor characteristic analysis method for preventing corrosion of a tungsten plug and belongs to the technical field of semiconductors. The method comprises the stepsthat a sample to be analyzed is cut in a wafer, and grinding liquid with the preset concentration is prepared; a passivation layer and a metal lamination layer of the sample to be analyzed are removeduntil a first metal layer is presented; the prepared grinding liquid with the preset concentration is used and matched with the preset rotation speed of a polishing disk to remove the first metal layer until a tungsten plug layer is presented; the sample which presents the tungsten plug layer is subjected to characteristic analysis. According to the semiconductor characteristic analysis method, the safe and environment friendly grinding liquid with the preset concentration is prepared, by matching with the certain rotation speed of the polishing disk, the first metal layer of the sample to beanalyzed is removed, the electrochemical reaction of the tungsten plug is effectively inhibited, then the completeness of the tungsten plug is guaranteed so that complete device standardization can be conducted on the tungsten plug layer, and the mistaken judgement of characteristic analysis due to sample processing problems is avoided.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a semiconductor characteristic analysis method for preventing tungsten plug corrosion. Background technique [0002] With the development of integrated circuit technology, the degree of integration is getting higher and higher, and the required integrated circuit manufacturing technology is becoming more and more sophisticated, which is mainly reflected in the fact that the size of the device is getting smaller and smaller, and the smaller device size means higher level technology. In general, integrated circuit chips include a large number of dense areas with repetitive structures and empty areas with non-repetitive structures for special functions. Whether it is high-end technology products (65nm and above) or low-end technology products (below 65nm), characteristic analysis is an indispensable step in the production process of integrated circuits, and in the method of ...

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Problems solved by technology

[0003] However, since the commonly used polishing liquid is alkaline, when grinding to the tungsten plug (CT) layer, tungsten may be corroded due to the electrochemical reaction of tungsten, resulting in the formation of voids in the tungsten plug, which will affect the subsequent chip failure analysis judge

Specifically, for low-end technology products, the grinding difference between the dense area and the empty area is not large. When the tungsten plug (CT) layer is ground, the tungsten plug can be kept intact and will not cause difficulties for subsequent analysis; however, For high-end technology products, the tungsten plugs in the dense area will be obviously corroded at high speed, which will cause difficulties for subsequent analysis. Therefore, for the dense areas of high-end technology products, low speed can be used to overcome the tungsten plugs However, for the tungsten plug in the open area, even with a low speed of less than 20 rpm, the corrosion of the tungsten plug is still unavoidable, making subsequent tungsten plug profile analysis and device measurement impossible.

The three-dimensional memory with high integration and high storage capacity is in the ranks of high-end technology products, so it also faces the problem of corrosion of tungsten plugs in the above failure analysis

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