Method for observing TSV (through-silicon-via) copper crystalline grains

Abstract

The invention relates to the field of microelectronics, and discloses a method for observing TSV (through-silicon-via) copper crystalline grains. In the method disclosed by the invention, a polishing treatment is performed on to-be-observed electroplating copper by virtue of an ion beam; ion etching is performed on the surface of the polished electroplating copper by virtue of an ion beam; the section of the electroplating copper is observed to obtain the size and morphology of the electroplating copper crystalline grains finally. Therefore, the to-be-observed TSV electroplating copper cannot be damaged and stained during the polishing process, and a corrosion effect and an observation effect during a corrosion process for the to-be-observed TSV electroplating copper are improved; meanwhile, the cost of observation equipment is decreased, and the resolution ratio of the observation result is increased.

Description

technical field [0001] The invention relates to the field of microelectronics, in particular to the observation technology of TSV copper grains. Background technique [0002] High density and high performance are the current development trend of microelectronic packaging, and Through Silicon Vias ("TSV" for short) technology is one of the key packaging technologies to meet this development trend. TSV technology etches micro-holes on the silicon wafer, then fills the micro-holes with copper by electroplating, and then anneals at a high temperature of about 410 degrees to form through-holes through silicon wafer thinning. Combined with the rewiring process to form interconnections and integrate them into the package structure. [0003] In order to analyze the TSV electroplating copper process in the above process, the possible changes of packaged products using through-silicon vias TSV when they experience thermal shock and thermal cycle, and to find evidence for product reli...

AI Technical Summary

Problems solved by technology

[0005] The disadvantage of the existing method 1 is: the grinding and polishing of TSV electroplated copper is carried out mechanically by using precision sandpaper and polishing cloth, etc. During the grinding and polishing process, damage to the sample surface, uneven grinding and polishing, and contamination by grinding and polishing debris will occur. problem, affecting follow-up observation

After grinding and polishing, TSV electroplating copper needs to be corroded by corrosive liquid. The corrosion effect is affected by copper metal process, liquid formula, ambient temperature, grinding and polishing roughness, etc. It is difficult to control the reaction time and speed of corrosive liquid and metal. The reproducibility of the effect is poor, and the observation effect is poor

The disadvantage of the existing method 2 is that the price of EBSD equipment is relatively expensive, and the analysis cost is higher than that of scanning electron microscope observation

Moreover, the spatial resolution of EBSD is lower than direct observation by scanning electron microscopy

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