Comparison of Gettering Techniques by Means of Intentional Quantitative Cu Contamination

Gettering is a very important technique for the LSI process. The effects of gettering techniques such as intrinsic gettering (IG), backside damage (BD), and polysilicon gettering (PG) were investigated by the MOS c-t method after intentional quantitative Cu contamination. These three techniques showed different gettering behaviors in the heat treatments simulating a device heat process. IG and BD were not effective in the beginning of the heat process, but they began to show stronger gettering effects with heat treatments and gained sufficient abilities. The IG kept its effect until the end of the heat process, but BD's effect decreased with subsequent heat treatments. PG had a sufficient gettering effect from the beginning of the heat process, but PG also showed a decrease of gettering effect at the end of the heat process.