EP0171949A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Microwave plasma etching apparatus
Assignee: Fujitsu Ltd
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Filing: 1985-07-23
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Granted: —
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Expires: 2005-07-23
Abstract
Abstract In a microwave plasma etching apparatus capable of forming a micro-pattern on an IC substrate, and having a substantially anisotropic etching ability, a microwave discharged plasma is generated from a gas with a relatively low pressure such as 10 -3 to 10 -4 Torr, whereby the mean free path of the gas molecules is sufficiently long as to exceed the dimensions of the structure of the etching apparatus. A magnetic mirror generating means (36) is disposed between a plasma generation chamber (35) and a reaction chamber (40) wherein the substrate (21) is mounted. Plasma discharge is enhanced by a cyclotron resonance magnetic field intensity (Pc) corresponding to the frequency of the microwave power applied to the piasma generation chamber (35). For the most part. electrons involved in the plasma are prevented from intruding into the reaction chamber, thereby eliminating generation of new radicals which might otherwise occur in the reaction cnamber and adversely affect the anisotropic etching ability
Inventors
- 👤 Shuzo C/O Fujitsu Limited Fujimura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 05:43
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/32431; H01J37/32623; H01J37/30; H01J37/305; H01J37/3053; H01J37/32009; H01J37/32192; H01J37/32201; H01J37/32357; H01J37/3266; H01J37/32678; H10; H10P; H10P72/00; H10P72/04; H10P72/0402; H10P72/0418; H10P72/0421
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
171 words
Microwave plasma etching apparatus, comprising a plasma generation chamber, wherein plasma is generated when the apparatus is in use, a reaction chamber, wherein a workpiece to be etched is held when the apparatus is in use, a connecting chamber, connecting the plasma generation chamber and the reaction chamber in vacuum-tight fashion, means operable to deliver microwave power, at a predetermined frequency, into the plasma generation chamber, means operable to introduce gas into the plasma generation chamber, and to maintain predetermined gas pressure in the chambers, and magnetic field generation means, operable to generate a magnetic field providing a magnetic field intensity distribution having a cyclotron resonance point, at which, in correspondence to the said predetermined frequency, cyclotron resonance of electrons is caused in the said plasma when the apparatus is in use, and having a peak value point, affording a magnetic mirror such that electrons in the plasma are for the greater part prevented from intruding from the plasma generation chamber into the reaction chamber when the apparatus is in use.
Claim 2
Dependent Claim
171 words
Microwave plasma etching apparatus, comprising a plasma generation chamber, wherein plasma is generated when the apparatus is in use, a reaction chamber, wherein a workpiece to be etched is held when the apparatus is in use, a connecting chamber, connecting the plasma generation chamber and the reaction chamber in vacuum-tight fashion, means operable to deliver microwave power, at a predetermined frequency, into the plasma generation chamber, means operable to introduce gas into the plasma generation chamber, and to maintain predetermined gas pressure in the chambers, and magnetic field generation means, operable to generate a magnetic field providing a magnetic field intensity distribution having a cyclotron resonance point, at which, in correspondence to the said predetermined frequency, cyclotron resonance of electrons is caused in the said plasma when the apparatus is in use, and having a peak value point, affording a magnetic mirror such that electrons in the plasma are for the greater part prevented from intruding from the plasma generation chamber into the reaction chamber when the apparatus is in use.
Claim 3
Dependent Claim
23 words
Apparatus as claimed in claim 1, wherein the predetermined gas pressure is less than 10 -3 Torr, for example approximately 10 -4 Torr.
Claim 4
Dependent Claim
84 words
Apparatus as claimed in claim 1 or 2, wherein the connecting chamber, and the reaction and plasma generation chambers, are so configured as to provide a collimation effect, whereby only those ions and radicals, generated in the plasma when the apparatus is in use, which travel in a selected range of directions such that they will impinge substantially perpendicularly upon a surface of the workpiece properly held in the reaction chamber when the apparatus is in use, are allowed to impinge upon that surface.
Claim 5
Dependent Claim
32 words
Apparatus as claimed in claim 1, 2 or 3, wherein the said peak value point is located between the said cyclotron resonance point and the workpiece properly held in the reaction chamber.
Claim 6
Dependent Claim
36 words
Apparatus as claimed in claim 4, wherein the magnetic field intensity distribution has a further peak value point located at that side of the plasma generation chamber away from the connecting chamber (and the reaction chamber).
Claim 7
Dependent Claim
43 words
Apparatus as claimed in any preceding claim, wherein the predetermined frequency is approximately 24.5 GH z, and magnetic field intensities at the cyclotron resonance point and the peak value point of claim 1 are 875 Gauss, and 1.5 KGauss to 2.5 KGauss respectively.
Claim 8
Dependent Claim
22 words
Apparatus as claimed in any preceding claim, wherein the mirror ratio of the magnetic mirror is in the range 2 to 3.
Claim 9
Dependent Claim
18 words
Apparatus as claimed in any preceding claim, wherein the magnetic field generation means comprise at least one solenoid.
Claim 10
Dependent Claim
14 words
Apparatus as claimed in any preceding claim, wherein the chambers are formed of aluminium.
Claim 11
Dependent Claim
49 words
Apparatus as claimed in any preceding claim, further comprising a shielding filter, positioned between the peak value point of claim 1 and the reaction chamber, serving to prevent leakage of microwave power into the reaction chamber, the filter being provided with holes to allow passage of radicals and ions.
References Cited (Backward Citations)
No citation records indexed.
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