Impurity ion segregation precluding layer, fabrication method thereof, isolation structure for semiconductor device using the impurity ion segregation precluding layer and fabricating method thereof

摘要

The present invention relates to the impurity ion segregation precluding layer, the fabrication method thereof, the isolation structure for the semiconductor device using the segregation precluding layer and the fabrication method thereof, which are provided to prevent impurity ions from segregating into a device isolation region in a semiconductor substrate and eventually restrain decrease in a threshold voltage due to the segregation of impurity ion, particularly, boron ions in the semiconductor substrate. The isolation structure of the semiconductor device is fabricated by forming a trench in a portion of the semiconductor substrate; placing the semiconductor substrate into a high-temperature furnace; annealing the semiconductor substrate flowing a nitride gas at about 20 l/min into the furnace; and filling an insulator in the trench. Thus, an impurity ion segregation precluding film is formed on a surface of the trench at a thickness of 1-10A in the annealing process using the nitride gas, so that the decrease in the threshold voltage of the semiconductor device is restrained and thus the semiconductor device can stably operate.