US5840200A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing semiconductor devices
Assignee: Panasonic Holdings Corp
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Filing: 1997-01-24
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Granted: 1998-11-24
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Expires: 2017-01-24
Abstract
Abstract A device insulating film, a lower-layer platinum film, a ferroelectric film, an upper-layer platinum film, and a titanium film are sequentially formed on a semiconductor substrate in this order. On the titanium film, a photoresist mask is further formed in a desired pattern. The thickness of the titanium film is adjusted to be 1/10 or more of the total thickness of a multilayer film consisting of the upper-layer platinum film, the ferroelectric film, and the lower-layer platinum film. The titanium film is then subjected to dry etching and the photoresist film is removed by ashing process. The titanium film thus patterned is used as a mask in etching the upper-layer platinum film, the ferroelectric film, and the lower-layer platinum film by a dry-etching method using a plasma of a gas mixture of chlorine and oxygen in which the volume concentration of oxygen gas is adjusted to be 40%. During the dry-etching process, the titanium film is oxidized to provide a high etching selectivity. Subsequently, the titanium film is removed by dry etching using a plasma of chlorine gas.
Inventors
- 👤 Satoshi Nakagawa
- 👤 Toyoji Ito
- 👤 Yoji Bito
- 👤 Yoshihisa Nagano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:44
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/60; H10D1/68; H10D1/682; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/28; H10P50/282; H10P50/283; H10P50/285
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
87 words
A method of manufacturing semiconductor devices, comprising the steps of: forming a film to be etched on a semiconductor substrate, said film to be etched being made of at least one of a ferroelectric material, a high dielectric constant material, and platinum; forming a patterned mask made of a metal to be oxidized on said film to be etched; and selectively etching said film to be etched by using said patterned mask as an etching mask and a plasma of a gas mixture of chlorine and oxygen.
Claim 2
Independent Claim
87 words
A method of manufacturing semiconductor devices, comprising the steps of: forming a film to be etched on a semiconductor substrate, said film to be etched being made of at least one of a ferroelectric material, a high dielectric constant material, and platinum; forming a patterned mask made of a metal to be oxidized on said film to be etched; and selectively etching said film to be etched by using said patterned mask as an etching mask and a plasma of a gas mixture of chlorine and oxygen.
Claim 3
Dependent Claim
35 words
A method according to claim 1, wherein said step of forming the mask comprises the step of forming a film made of at least one of titanium, a titanium compound, and an alloy containing titanium.
Claim 4
Dependent Claim
37 words
A method according to claim 1, wherein said step of selectivity etching the film to be etched comprises the step of adjusting a volume concentration of oxygen gas in said gas mixture to be 30% or more.
Claim 5
Independent Claim
105 words
A method of manufacturing semiconductor devices, comprising the steps of: forming a film to be etched on a semiconductor substrate, said film to be etched being made of at least one of a ferroelectric material and a high dielectric constant material; forming a patterned multilayer mask on said film to be etched, said multilayer mask comprising a lower-layer mask made of an insulating material and an upper-layer mask made of a metal likely to be oxidized on said lower-layer mask; selectively etching said film to be etched by using an oxidizing and halogenating gas plasma; and removing said upper-layer mask while leaving said lower-layer mask.
Claim 6
Independent Claim
105 words
A method of manufacturing semiconductor devices, comprising the steps of: forming a film to be etched on a semiconductor substrate, said film to be etched being made of at least one of a ferroelectric material and a high dielectric constant material; forming a patterned multilayer mask on said film to be etched, said multilayer mask comprising a lower-layer mask made of an insulating material and an upper-layer mask made of a metal likely to be oxidized on said lower-layer mask; selectively etching said film to be etched by using an oxidizing and halogenating gas plasma; and removing said upper-layer mask while leaving said lower-layer mask.
Claim 7
Dependent Claim
25 words
A method according to claim 4, wherein said step of forming the lower-layer mask comprises the step of forming a film made of silicon oxide.
Claim 8
Dependent Claim
36 words
A method according to claim 4, wherein said step of forming the upper-layer mask comprises the step of forming a film made of at least one of titanium, a titanium compound, and an alloy containing titanium.
Claim 9
Dependent Claim
43 words
A method according to claim 6, wherein said step of removing the upper-layer mask comprises the step of etching said upper-layer mask by using a reducing gas plasma under such a condition that titanium and titanium oxide are etched at the same rate.
Claim 10
Dependent Claim
26 words
A method according to claim 7, wherein said step of removing the upper-layer mask comprises the step of selecting a reducing gas plasma of boron trichloride.
Claim 11
Independent Claim
104 words
A method of manufacturing semiconductor devices, comprising the steps of: forming a film to be etched on a semiconductor substrate, said film to be etched being made of at least one of a ferroelectric material and a high dielectric constant material; forming an electrode pattern made of platinum on said film to be etched; forming a patterned mask made of an insulating material on said film to be etched, said patterned mask being larger than said electrode pattern and covering said electrode pattern; and selectively etching said film to be etched by using said patterned mask as an etching mask and a gas plasma.
Claim 12
Independent Claim
104 words
A method of manufacturing semiconductor devices, comprising the steps of: forming a film to be etched on a semiconductor substrate, said film to be etched being made of at least one of a ferroelectric material and a high dielectric constant material; forming an electrode pattern made of platinum on said film to be etched; forming a patterned mask made of an insulating material on said film to be etched, said patterned mask being larger than said electrode pattern and covering said electrode pattern; and selectively etching said film to be etched by using said patterned mask as an etching mask and a gas plasma.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-11-23 | 2002-05-25 | 2002-11-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-11-23 | 2006-05-25 | 2006-11-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-11-23 | 2010-05-25 | 2010-11-24 | $7700.00 | Window Closed / Lapsed |