Anova Law Group, PLLC
Method of forming connection holes
The present invention provides a method of forming connection holes. The method utilizes two different gases to perform two etching processes for the interlayer dielectric layer so as to form connection holes. The etching rate of the interlayer dielectric layer in the first etching process using the first etching gas is proportional to the size of the openings which defines the connection hole while the etching rate of the interlayer dielectric layer in the second etching process using the second etching gas is inversely related with size of the openings. According to the present invention, the first etching gas and the second etching gas compensate for each other to eliminate the loading effect, thus the connection holes are formed with almost the same depth. Therefore the damage of the etching stopper layer due to the high etching rate in the larger connection holes can be avoided, which prevents the excessive variation of the connecting resistance and expands the process window.
Shanghai Huali Microelectronics Corporation
H H H
H01L H01L H01L
inventional inventional inventional
Cheng Yuwen Yushu
Li Chen Yang