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US 7,022,616 B2Granted
High speed silicon etching method
AssigneesTokyo Electron Limited, Kabushiki Kaisha Toshiba
InventorsTakanori Mimura, Kazuya Nagaseki, Itsuko Sakai, Tokuhisa Ohiwa
Life of this patent
Estimating the term…
Abstract
This invention provides the following high-rate silicon etching method. An object to be processed W having a silicon region is so set as to be in contact with a process space in a process chamber that can be held in vacuum. An etching gas is introduced into the process space to form a gas atmosphere at a gas pressure of 13 Pa to 1,333 Pa (100 mTorr to 10 Torr). A plasma is generated upon application of RF power. In the plasma, the sum of the number of charged particles such as ions and the number of radicals increases, and etching of the silicon region is performed at a higher rate than in conventional etching.
Claims18
A high-rate silicon etching method wherein, by using a magnetron etching apparatus having
- a process chamber which can be held in vacuum,
- a pair of electrodes provided in the process chamber to sandwich a process space,
- RF power supply means for applying RF power of not less than 27 MHz for plasma generation to an electrode where an object to be processed is held, thereby forming an RF electric field in the process space,
- an etching gas inlet mechanism which introduces an etching gas containing a fluorine compound gas into the process space, thereby forming a gas atmosphere, and
- magnetic field forming means for forming in the process space a magnetic field perpendicular to the RF electric field and directed in one direction,
- when etching a silicon region at a high rate of not less than 20 μm/min such that orthogonal electromagnetic fields are formed in the process space to generate a plasma in the gas atmosphere, and an object to be processed is set such that the silicon region of an etching target surface of the object to be processed is in contact with the plasma, etching is performed by setting a gas pressure in the process space to 13 Pa to 1,333 Pa (100 mTorr to 10 Torr), and
- wherein a distance between a plasma generation region in the process space and an etching surface of the object to be processed is not more than 20 mm.
4 more elements
A high-rate silicon etching method wherein, by using a magnetron etching apparatus having
- a process chamber which can be held in vacuum,
- a pair of electrodes provided in the process chamber to sandwich a process space,
- RF power supply means for applying RF power of not less than 27 MHz for plasma generation to an electrode where an object to be processed is held, thereby forming an RF electric field in the process space,
- an etching gas inlet mechanism which introduces an etching gas containing a fluorine compound gas and oxygen into the process space, thereby forming a gas atmosphere, and
- magnetic field forming means for forming in the process space a magnetic field perpendicular to the RF electric field and directed in one direction,
- when etching a silicon region such that orthogonal electromagnetic fields are formed in the process space to generate a plasma in the gas atmosphere, and an object to be processed is set such that the silicon region of an etching target surface of the object to be processed is in contact with the plasma, etching is performed by setting a gas pressure in the process space to 13 Pa to 1,333 Pa (100 mTorr to 10 Torr),
- wherein
- the etching gas contains SF6 and O2, and O2/SF6 is 0.1 to 0.5.
5 more elements
A high-rate silicon etching method wherein, by using a magnetron etching apparatus having
- a process chamber which can be held in vacuum,
- a pair of electrodes provided in the process chamber to sandwich a process space,
- RF power supply means for applying RF power of not less than 27 MHz for plasma generation to an electrode where an object to be processed is held, thereby forming an RF electric field in the process space,
- an etching gas inlet mechanism which introduces an etching gas containing a fluorine compound gas into the process space, thereby forming a gas atmosphere, and
- magnetic field forming means for forming in the process space a magnetic field perpendicular to the RF electric field and directed in one direction,
- when etching a silicon region such that orthogonal electromagnetic fields are formed in the process space to generate a plasma in the gas atmosphere, and an object to be processed is set such that the silicon region of an etching target surface of the object to be processed is in contact with the plasma, etching is performed by setting a gas pressure in the process space to 13 Pa to 1,333 Pa (100 mTorr to 10 Torr),
- wherein
- the etching gas contains SF6 and C4F8, and C4F8/SF6 is 0.3 to 0.6.
5 more elements
A high-rate silicon etching method wherein, by using a magnetron etching apparatus having
- a process chamber which can be held in vacuum,
- a pair of electrodes provided in the process chamber to sandwich a process space, first RF power supply means for applying RF power for plasma generation to an electrode where an object to be processed is held, thereby forming an RF electric field in the process space,
- an etching gas inlet mechanism which introduces an etching gas into the process space, thereby forming a gas atmosphere,
- magnetic field forming means for forming in the process space a magnetic field perpendicular to the RF electric field and directed in one direction, and
- a second RF power supply which applies RF power different in frequency from the RF power from the first RF power supply to an electrode where the object to be processed is held,
- when etching a silicon region at a high rate such that orthogonal electromagnetic fields are formed in the process space to generate a plasma in the gas atmosphere, and an object to be processed is set such that the silicon region of an etching target surface of the object to be processed is in contact with the plasma, RF power which has a frequency lower than that of the RF power for plasma generation from the first RF power supply means and not less than 2 MHz and is output from the second power supply is superposed on the RF power for plasma generation, and etching is performed by setting a gas pressure in the process space to 13 Pa to 1,333 Pa (100 mTorr to 10 Torr).
3 more elements
A high-rate silicon etching method wherein, by using a magnetron etching apparatus having
- a process chamber which can be held in vacuum,
- a pair of electrodes provided in the process chamber to sandwich a process space,
- RF power supply means for applying RF power of not less than 27 MHz for plasma generation to an electrode where an object to be processed is held, thereby forming an RF electric field in the process space,
- an etching gas inlet mechanism which introduces an etching gas containing a fluorine compound gas into the process space, thereby forming a gas atmosphere, and
- magnetic field forming means for forming in the process space a magnetic field perpendicular to the RF electric field and directed in one direction,
- when etching a silicon region such that orthogonal electromagnetic fields are formed in the process space to generate a plasma in the gas atmosphere, and an object to be processed is set such that the silicon region of an etching target surface of the object to be processed is in contact with the plasma, etching is performed by setting a gas pressure in the process space to 13 Pa to 1,333 Pa (100 mTorr to 10 Torr),
- wherein the object to be processed having the silicon region is a single-crystal silicon substrate, and
- after the step of etching the single-crystal silicon substrate by the high-rate silicon etching method, an opposite surface of the silicon substrate is entirely ground or etched, so a hole or groove formed in the silicon substrate by the high-rate silicon etching method extends through the silicon substrate.
5 more elements
A high-rate silicon etching method of etching a silicon region in order to form a hole, groove, or through hole in a silicon substrate, wherein
- in a process space where the silicon substrate is to be set and a plasma for etching is to be generated, RF power is applied to an electrode on which the silicon substrate is mounted, thereby generating the plasma, and the gas pressure in the process space is set to 13 Pa to 1,333 Pa (100 mTorr to 10 Torr),
- a gas pressure of an etching gas containing a fluorine compound gas in the process space is so increased as to increase the number of radicals as neutral particles contributing to silicon etching and the number of charged ion particles, regardless of a plasma density in the process space, thereby setting an etching rate in the silicon region to be not less than 20 μm/min.
Dependencies are inferred from the claim text.