Control of mask CD
A method for controlling a critical dimension of a mask layer is described. The method includes receiving a first primary parameter level, a second primary parameter level, a first secondary parameter level, a second secondary parameter level, and a third secondary parameter level. The method also includes generating a primary signal having the first primary parameter level, and transitioning the primary signal from the first primary parameter level to the second primary parameter level. The method further includes generating a secondary radio frequency (RF) signal having the first secondary parameter level, and transitioning the secondary RF signal from the first secondary parameter level to the second secondary parameter level. The method includes transitioning the secondary RF signal from the second secondary parameter level to the third secondary parameter level.
1 . A method for controlling a critical dimension of a mask layer of a substrate, comprising:
receiving, by a primary radio frequency (RF) generator, a first primary parameter level and a second primary parameter level;
receiving, by a secondary RF generator, a first secondary parameter level, a second secondary parameter level, and a third secondary parameter level;
generating, by the primary RF generator, a primary RF signal having the first primary parameter level, wherein the primary RF signal is a sine wave;
transitioning, by the primary RF generator during a clock cycle, the primary RF signal from the first primary parameter level to the second primary parameter level;
generating, by the secondary RF generator, a secondary RF signal having the first secondary parameter level, wherein the secondary RF signal is a sine wave;
transitioning, by the secondary RF generator, the secondary RF signal from the first secondary parameter level to the second secondary parameter level during the clock cycle;
transitioning, by the secondary RF generator, the secondary RF signal from the second secondary parameter level to the third secondary parameter level during the clock cycle,
wherein said transitioning of the primary RF signal from the first primary parameter level to the second primary parameter level occurs in synchronization with said transitioning of the secondary RF signal from the first secondary parameter level to the second secondary parameter level,
sending the primary RF signal from the primary RF generator to a match that is coupled to an electrode of a plasma chamber; and
sending the secondary RF signal from the secondary RF generator to the match,
wherein the second secondary parameter level is generated to control the critical dimension of the mask layer.
2 . The method of claim 1 , wherein the second secondary parameter level ranges from 100 watts to 1000 watts.
3 . The method of claim 1 , further comprising receiving a measurement of the critical dimension, wherein the second secondary parameter level is based on the measurement of the critical dimension.
4 . The method of claim 3 , wherein the measurement of the critical dimension is less than a predetermined critical dimension, the method comprising:
modifying a fourth secondary parameter level to the second secondary parameter level after receiving an indication that the measurement of the critical dimension is less than the predetermined critical dimension.
5 . The method of claim 4 , further comprising changing a duty cycle of the fourth secondary parameter level after receiving the indication that the measurement of the critical dimension is less than the predetermined critical dimension.
6 . The method of claim 1 , wherein the second secondary parameter level has a duty cycle that is one to three times a duty cycle of the first secondary parameter level.
7 . The method of claim 1 , wherein the second secondary parameter level has a duty cycle that is four to five times a duty cycle of the first secondary parameter level.
8 . The method of claim 1 , wherein the critical dimension includes a distance between a first passivation layer adjacent to the mask layer and a second passivation layer adjacent to the mask layer, wherein the first passivation layer faces the second passivation layer.
9 . The method of claim 1 , wherein said transitioning of the primary RF signal from the first primary parameter level to the second primary parameter level occurs in synchronization with said transitioning of the secondary RF signal from the first secondary parameter level to the second secondary parameter level when said transitioning of the primary RF signal from the first primary parameter level to the second primary parameter level is controlled to be initiated at the same time as said transitioning of the secondary RF signal from the first secondary parameter level to the second secondary parameter level.
10 . The method of claim 1 , wherein during the third secondary parameter level and a first portion of the second primary parameter level, a deposition operation occurs on the mask layer, wherein during the second secondary parameter level and a second portion of the second primary parameter level, a trade-off between the critical dimension and clogging of the mask layer occurs, wherein during the first primary parameter level and the first secondary parameter level, the substrate is etched.
11 . The method of claim 1 , wherein the second secondary parameter level is lower than the first secondary parameter level and the third secondary parameter level is lower than the second secondary parameter level.
12 . The method of claim 1 , wherein the third secondary parameter level is zero.
13 . The method of claim 1 , wherein the second secondary parameter level is lower than the first secondary parameter level and the third secondary parameter level is greater than the second secondary parameter level.
14 . The method of claim 1 , wherein the second secondary parameter level is zero.