Method for improved sputter etch processing

Claim 2

Method for processing a semiconductor substrate in a chamber comprising the steps of: (a) establishing preprocess conditions in the chamber; (b) executing a two-step plasma ignition; (c) processing the substrate; (d) executing a two-step plasma power down; and (e) executing a two-step substrate dechuck.

Claim 3

The method of claim 1 wherein step (a) further comprises: (i) chucking the substrate; (ii) flowing a backside gas to the substrate to establish a backside gas pressure; and (iii) stabilizing an atmosphere in the chamber.

Claim 4

The method of claim 2 wherein step (i) further comprises applying a chucking voltage of approximately 250 volts to a substrate support within the chamber.

Claim 5

The method of claim 2 wherein step (ii) further comprises flowing the backside gas at a flow rate of approximately 4 sccm for approximately 10 seconds.

Claim 6

The method of claim 2 wherein step (iii) further comprises: introducing a first flow of process gas at a flow rate of approximately 100 sccm; introducing a second flow of process gas at a flow rate of approximately 5 sccm; and reducing the backside gas flow to approximately 1 sccm for approximately 5 seconds.

Claim 7

The method of claim 1 wherein step (b) further comprises applying an RF bias power and an RF coil power to the chamber.

Claim 8

The method of claim 6 wherein the RF bias power is approximately 200 Watts at a frequency of approximately 13.56 Mhz and the RF coil power is approximately 300 Watts at a frequency of approximately 400 Khz.

Claim 9

The method of claim 6 wherein the RF coil power is applied approximately 0.5 seconds after the RF bias power is applied.

Claim 10

The method of claim 7 wherein step (c) further comprises increasing the RF bias power to approximately 300 Watts and reducing the first flow of process gas to approximately 0 sccm for approximately 60 seconds.

Claim 11

The method of claim 7 wherein step (d) further comprises increasing the RF coil power to approximately 500 Watts and reducing a backside gas flow to approximately 0 sccm for approximately 2 seconds.

Claim 12

The method of claim 10 wherein step (d) further comprises decreasing the RF bias power to approximately 150 Watts for approximately 2 seconds.

Claim 13

The method of claim 7 wherein step (e) further comprises decreasing the RF bias power to approximately 1 Watt for approximately 6 seconds.

Claim 14

The method of claim 12 wherein step (e) further comprises reducing the chucking voltage to approximately 1 volt for approximately 5 seconds.

Claim 15

The method of claim 1 further comprising the steps of: (f) purging the chamber; and (g) pumping the chamber.

Claim 16

The method of claim 14 wherein step (f) further comprises flowing a purge gas into the chamber at a flow rate of approximately 25 sccm for approximately 5 seconds.

Claim 17

The method of claim 15 wherein the purge gas is Argon.

Claim 18

The method of claim 14 wherein the chamber is pumped for approximately 5 seconds.

Claim 19

Method for processing a semiconductor substrate in a chamber comprising the steps of: (a) chucking the substrate; (b) flowing a backside gas to the substrate at a flow rate of approximately 4 sccm for approximately 10 seconds; (c) introducing a first flow of process gas to the chamber at a flow rate of approximately 100 sccm; (d) introducing a second flow rate of a process gas to the chamber at a flow rate of approximately 5 sccm; (e) reducing the backside gas flow to approximately 1 sccm for approximately 5 seconds; (f) applying an RF bias power to the chamber of approximately 200 watts at a frequency of approximately 13.56 Mhz and applying an RF coil power approximately 0.5 seconds after applying the RF bias power, the RF coil power being approximately 300 watts at a frequency of approximately 400 Khz; (g) increasing the RF bias power to approximately 300 watts and reducing the first flow of process gas to approximately 0 sccm; (h) processing the substrate; (i) increasing the RF coil power to approximately 500 watts and reducing a backside gas flow to approximately 0 sccm for approximately 2 seconds; (j) decreasing the RF bias power to approximately 150 watts for approximately 2 seconds; (k) decreasing the RF bias power to approximately 1 watt for approximately 6 seconds; (l) reducing the chucking voltage to approximately 1 volt for approximately 5 seconds; (m) flowing a purge gas into the chamber at a flow rate of approximately 25 sccm for approximately 5 seconds; and (n) pumping the chamber for approximately 5 seconds.

Claim 20

Method for processing a semiconductor substrate in a chamber comprising the steps of: (a) chucking the substrate; (b) flowing a backside gas to the substrate at a flow rate of approximately 4 sccm for approximately 10 seconds; (c) introducing a first flow of process gas to the chamber at a flow rate of approximately 100 sccm; (d) introducing a second flow rate of a process gas to the chamber at a flow rate of approximately 5 sccm; (e) reducing the backside gas flow to approximately 1 sccm for approximately 5 seconds; (f) applying an RF bias power to the chamber of approximately 200 watts at a frequency of approximately 13.56 Mhz and applying an RF coil power approximately 0.5 seconds after applying the RF bias power, the RF coil power being approximately 300 watts at a frequency of approximately 400 Khz; (g) increasing the RF bias power to approximately 300 watts and reducing the first flow of process gas to approximately 0 sccm; (h) processing the substrate; (i) increasing the RF coil power to approximately 500 watts and reducing a backside gas flow to approximately 0 sccm for approximately 2 seconds; (j) decreasing the RF bias power to approximately 150 watts for approximately 2 seconds; (k) decreasing the RF bias power to approximately 1 watt for approximately 6 seconds; (l) reducing the chucking voltage to approximately 1 volt for approximately 5 seconds; (m) flowing a purge gas into the chamber at a flow rate of approximately 25 sccm for approximately 5 seconds; and (n) pumping the chamber for approximately 5 seconds.

Claim 21

The method of claim 18 wherein step (c) is conducted for approximately 5 seconds.

Claim 22

The method of claim 18 wherein step (h) is conducted for approximately 60 seconds.

Claim 23

Method for processing a semiconductor substrate in a chamber comprising the steps of: (a) establishing preprocess conditions in the chamber; (b) executing a two-step plasma ignition in which bias power is applied to an electrostatic chuck and coil power is applied to a coil; (c) processing the substrate; (d) executing a two-step plasma power reduction in which the coil power is increased and the bias power is decreased; and (e) executing a two-step substrate dechuck in which the bias power is decreased and a chucking voltage applied to the electrostatic chuck is reduced.

Claim 24

Method for processing a semiconductor substrate in a chamber comprising the steps of: (a) establishing preprocess conditions in the chamber; (b) executing a two-step plasma ignition in which bias power is applied to an electrostatic chuck and coil power is applied to a coil; (c) processing the substrate; (d) executing a two-step plasma power reduction in which the coil power is increased and the bias power is decreased; and (e) executing a two-step substrate dechuck in which the bias power is decreased and a chucking voltage applied to the electrostatic chuck is reduced.