Patent US6296987B1 successfully refreshed from Google Patents.
US6296987B1
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Method for forming different patterns using one mask
Assignee: United Microelectronics Corp
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Filing: 1999-10-20
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Granted: 2001-10-02
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Expires: 2019-10-20
Abstract
Abstract A method for forming different patterns using one phase shifting mask. The phase shifting mask has a bit line contact pattern and a node contact pattern thereon. The exposure pattern is changed by using different defocus conditions. In a first defocus situation, the bit line contact pattern and the node contact pattern of the PSM are simultaneously transferred to a photoresist layer. However, in a second defocus situation, only the bit line contact pattern is transferred to the photoresist layer. A phase shifting mask thus can be used in two different photolithography processes.
Inventors
- 👤 Benjamin Szu-Min Lin
- 👤 Chien-Li Kuo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 22:33
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70425; G03F7/70466; G03F1/00; G03F1/26; G03F1/30; G03F7/0035
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
207 words
A method for forming different patterns using one phase shifting mask, comprising the steps of: providing a semiconductor substrate, wherein at least one conductive structure with a spacer on its sidewall is formed thereon; forming a first dielectric layer over the semiconductor substrate, the first dielectric layer having a planar top surface; forming a first photoresist layer on the first dielectric layer; providing a mask over the first photoresist layer, wherein the mask comprises a bit line contact pattern and a node contact pattern; performing a first photolithography process to transfer the bit line contact pattern and the node contact pattern to the first photoresist layer; etching the first dielectric layer according to the bit line contact pattern and the node contact pattern of the first photoresist layer to form a bit line contact opening and a node contact opening; removing the first photoresist layer; forming a conductive material within the bit line contact opening and the node contact opening; forming a second dielectric layer on the first dielectric layer and on the conductive material; providing a second photoresist layer over the second dielectric layer; and performing a second photolithography process using the mask to transfer only the bit line contact pattern to the second photoresist layer.
Claim 2
Independent Claim
207 words
A method for forming different patterns using one phase shifting mask, comprising the steps of: providing a semiconductor substrate, wherein at least one conductive structure with a spacer on its sidewall is formed thereon; forming a first dielectric layer over the semiconductor substrate, the first dielectric layer having a planar top surface; forming a first photoresist layer on the first dielectric layer; providing a mask over the first photoresist layer, wherein the mask comprises a bit line contact pattern and a node contact pattern; performing a first photolithography process to transfer the bit line contact pattern and the node contact pattern to the first photoresist layer; etching the first dielectric layer according to the bit line contact pattern and the node contact pattern of the first photoresist layer to form a bit line contact opening and a node contact opening; removing the first photoresist layer; forming a conductive material within the bit line contact opening and the node contact opening; forming a second dielectric layer on the first dielectric layer and on the conductive material; providing a second photoresist layer over the second dielectric layer; and performing a second photolithography process using the mask to transfer only the bit line contact pattern to the second photoresist layer.
Claim 3
Dependent Claim
16 words
A method according to claim 1 , wherein the mask comprises an alternating phase shifting mask.
Claim 4
Dependent Claim
26 words
A method according to claim 1 , wherein a phase of the bit line contact pattern and a phase of the node contact pattern are complementary.
Claim 5
Dependent Claim
28 words
A method according to claim 1 , wherein the bit line contact pattern is at a 0° phase, and the node contact pattern is at a 180° phase.
Claim 6
Dependent Claim
28 words
A method according to claim 1 , wherein a window of focus deviation of the bit line contact pattern is larger than that of the node contact pattern.
Claim 7
Independent Claim
82 words
A method for forming different patterns using one phase shifting mask, comprising the steps of: providing a phase shifting mask comprising a bit line contact pattern and a node contact pattern; performing a first photolithography process under a first exposure condition to transfer the bit line contact pattern and the node contact pattern to a first photoresist layer; and performing a second photolithography process under a second exposure condition to transfer only the bit line contact pattern to a second photoresist layer.
Claim 8
Independent Claim
82 words
A method for forming different patterns using one phase shifting mask, comprising the steps of: providing a phase shifting mask comprising a bit line contact pattern and a node contact pattern; performing a first photolithography process under a first exposure condition to transfer the bit line contact pattern and the node contact pattern to a first photoresist layer; and performing a second photolithography process under a second exposure condition to transfer only the bit line contact pattern to a second photoresist layer.
Claim 9
Dependent Claim
18 words
A method according to claim 6 , wherein the phase shifting mask comprises an alternating phase shifting mask.
Claim 10
Dependent Claim
26 words
A method according to claim 6 , wherein a phase of the bit line contact pattern and a phase of the node contact pattern are complementary.
Claim 11
Dependent Claim
28 words
A method according to claim 6 , wherein the bit line contact pattern is at a 0° phase, and the node contact pattern is at a 180° phase.
Claim 12
Dependent Claim
16 words
A method according to claim 6 , wherein the first exposure condition is a complete focus.
Claim 13
Dependent Claim
19 words
A method according to claim 6 , wherein the first exposure condition is a defocus of about −0.2 μm.
Claim 14
Dependent Claim
19 words
A method according to claim 6 , wherein the second focus condition is a defocus of about +0.4 μm.
Claim 15
Dependent Claim
28 words
A method according to claim 6 , wherein a window of focus deviation of the bit line contact pattern is larger than that of the node contact pattern.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-10-01 | 2005-04-02 | 2005-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-10-01 | 2009-04-02 | 2009-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-10-01 | 2013-04-02 | 2013-10-02 | $7700.00 | Window Closed / Lapsed |