Plasma-process system with improved end-point detecting scheme
First Claim
1. A plasma-process method comprising the steps of:
- placing an object at a predetermined position within a reaction chamber in which to generate plasma, said object having a silicon dioxide film formed on at least a part of a surface thereof;
conducting a CF-based gas used as reactant gas and a predetermined additional gas into said reaction chamber;
generating plasma in said reaction chamber, thereby to perform etching the silicon dioxide film formed on the object;
monitoring luminous intensity of active species present in the CF-based gas, which contributes to the etching anddetecting an end point of the etching from a monitored luminous intensity of the active species, without influence of influence of an emission spectrum of the additional gas.
1 Assignment
0 Petitions
Accused Products
Abstract
In one aspect of the invention, CHF3 gas and CF4 gas (i.e., reactant gases), and argon gas (i.e., plasma-stabilizing gas) are introduced into a vacuum chamber. RF power is then applied between the electrodes within the chamber, thereby generating plasma. The plasma is applied to a substrate placed in the chamber, thus etching the SiO2 film formed on the substrate. A spectrometer extracts a light beam of a desired wave-length, emitted from the CF2 radical which contributes to the etching. An end-point detecting section monitors the luminous intensity of the CF2 radical reacting with SiO2 during the etching. Once the SiO2 film has been etched away, the luminous intensity of the CF2 radical increases. Upon detecting this increase, the section determines that etching has just ended. The selected wavelength ranges from 310 nm to 236 nm, preferably being 219.0 nm, 230.0 nm, 211.2 nm, 232.5 nm, or any one ranging from 224 nm to 229 nm. In another aspect of the invention, the device attached to the observation window of the chamber removes products stuck to the window during the etching. The window thus cleaned, more light than otherwise passes through the window and reaches the spectrometer. This enables the section to detect even a slight change in the luminous intensity of the CF2 radical, thereby detecting the end point of etching with accuracy.
64 Citations
20 Claims
-
1. A plasma-process method comprising the steps of:
-
placing an object at a predetermined position within a reaction chamber in which to generate plasma, said object having a silicon dioxide film formed on at least a part of a surface thereof; conducting a CF-based gas used as reactant gas and a predetermined additional gas into said reaction chamber; generating plasma in said reaction chamber, thereby to perform etching the silicon dioxide film formed on the object; monitoring luminous intensity of active species present in the CF-based gas, which contributes to the etching and detecting an end point of the etching from a monitored luminous intensity of the active species, without influence of influence of an emission spectrum of the additional gas. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A plasma-process method comprising the steps of:
-
placing an object at a predetermined position within a reaction chamber in which to generate plasma, said object having a silicon dioxide film formed on at least a part of a surface thereof; conducting a CF-based gas used as reactant gas and a predetermined additional gas into said reaction chamber; generating plasma in said reaction chamber, thereby to perform etching the silicon dioxide film formed on the object; monitoring an intensity of a light beam emitted from the plasma and having a desired wavelength which falls within a range of 210 to 236 nm; and detecting an end point of the etching from a monitored intensity of the light beam having the desired wavelength, without influence of influence of an emission spectrum of the additional gas. - View Dependent Claims (9, 10, 11)
-
-
12. A plasma-process method comprising the steps of:
-
placing an object at a predetermined position within a reaction chamber in which to generate plasma, said object having a silicon dioxide film formed on at least a part of a surface thereof; conducting a CF-based gas used as reactant gas into said reaction chamber; generating plasma in said reaction chamber, thereby to perform etching the silicon dioxide film formed on the object; monitoring luminous intensity of active species present in the CF-based gas, which contributes to the etching; and detecting an end point of the etching from a monitored luminous intensity of the active species. - View Dependent Claims (13, 14, 15, 16, 17)
-
-
18. A plasma-process method comprising the steps of:
-
placing an object at a predetermined position within a reaction chamber in which to generate plasma, said object having a silicon dioxide film formed on at least a part of a surface thereof; conducting a CF-based gas used as a reactant gas into said reaction chamber; generating plasma in said reaction chamber, thereby to perform etching the silicon dioxide film formed on the object; monitoring an intensity of a light beam emitted from the plasma and having a desired wavelength which falls within a range of 210 to 236 nm; and detecting an end point of the etching from a monitored intensity of the light beam having the desired wavelength. - View Dependent Claims (19, 20)
-
Specification