Patent US6512504B1 successfully refreshed from Google Patents.
US6512504B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic device and electronic apparatus
Assignee: Semiconductor Energy Laboratory Co Ltd
•
Filing: 2000-04-18
•
Granted: 2003-01-28
•
Expires: 2020-04-18
Abstract
Abstract An EL display having high operating performance and reliability is provided. LDD regions 15 a through 15 d of a switching TFT 201 formed in a pixel are formed such that they do not overlap gate electrodes 19 a and 19 b to provide a structure which is primarily intended for the reduction of an off-current. An LDD region 22 of a current control TFT 202 is formed such that it partially overlaps a gate electrode 35 to provide a structure which is primarily intended for the prevention of hot carrier injection and the reduction of an off-current. Appropriate TFT structures are thus provided depending on required functions to improve operational performance and reliability.
Inventors
- 👤 Yukio Yamauchi
- 👤 Takeshi Fukunaga
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 10:15
CPC Classifications
H; H10; H10D; H10D86/00; H10D86/40; H10D86/481; H10D30/00; H10D30/01; H10D30/021; H10D30/031; H10D30/0312; H10D30/0314; H10D30/0321; H10D30/60; H10D30/67; H10D30/6704; H10D30/6713; H10D30/6715; H10D30/6719; H10D86/441; H10D86/471; H10D86/60; H10K; H10K59/00; H10K59/10; H10K59/12; H10K59/121; H10K59/1213; H10K59/1216; H10K59/131; G; G09; G09G; G09G2300/00; G09G2300/04; G09G2300/0421; G09G2300/0426; G09G2300/08; G09G2300/0809; G09G2300/0842; G09G2300/0861; H10D86/80; H10K2102/00; H10K2102/301; H10K2102/302; H10K2102/3023; H10K2102/3026; H10K59/30; H10K59/38
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
83 words
An electronic device having at least one pixel, said pixel comprising: a first TFT for switching, a second TFT for controlling current and an EL element connected to said second TFT; wherein an LDD (lightly-doped-drain) region formed in said first TFT does not overlap a gate electrode of said first TFT with a gate insulating film interposed, wherein an LDD region formed in said second TFT partially or entirely overlaps a gate electrode of said second TFT with a gate insulating film interposed.
Claim 2
Dependent Claim
83 words
An electronic device having at least one pixel, said pixel comprising: a first TFT for switching, a second TFT for controlling current and an EL element connected to said second TFT; wherein an LDD (lightly-doped-drain) region formed in said first TFT does not overlap a gate electrode of said first TFT with a gate insulating film interposed, wherein an LDD region formed in said second TFT partially or entirely overlaps a gate electrode of said second TFT with a gate insulating film interposed.
Claim 3
Dependent Claim
31 words
An electronic device according to claim 1 wherein a length of the LDD region overlapping said gate electrode of said second TFT is in the range from 1 to 3 μm.
Claim 4
Dependent Claim
40 words
An electronic device according to claim 1 wherein an n-type impurity element is contained in the LDD region of said second TFT at a concentration 2 to 10 times higher than that of the LDD region of said first TFT.
Claim 5
Dependent Claim
31 words
An electronic device according to claim 1 wherein the LDD region of said second TFT contains an n-type impurity element at a concentration 2×10 16 to 5×10 19 atoms/cm 3 .
Claim 6
Dependent Claim
31 words
An electronic device according to claim 1 wherein the LDD region of said first TFT contains an n-type impurity element at a concentration 1×10 16 to 5×10 18 atoms/cm 3 .
Claim 7
Dependent Claim
52 words
An electronic device according to claim 1 wherein said electronic device is selected from the group consisting of a video camera, a digital camera, a goggle type display, a navigation systems, a sound reproduction device, a note type personal computer, a game machine, a portable information terminal, and an image projection device.
Claim 8
Dependent Claim
80 words
An electronic device having at least one pixel, said pixel comprising: a first TFT for switching, a second TFT for controlling current and an EL element connected to said second TFT; wherein an LDD (lightly-doped-drain) region of said first TFT partially overlaps a gate electrode of said first TFT with a gate insulation film interposed, wherein an LDD region of said second TFT partially or entirely overlaps a gate electrode of said second TFT with a gate insulation film interposed.
Claim 9
Dependent Claim
80 words
An electronic device having at least one pixel, said pixel comprising: a first TFT for switching, a second TFT for controlling current and an EL element connected to said second TFT; wherein an LDD (lightly-doped-drain) region of said first TFT partially overlaps a gate electrode of said first TFT with a gate insulation film interposed, wherein an LDD region of said second TFT partially or entirely overlaps a gate electrode of said second TFT with a gate insulation film interposed.
Claim 10
Dependent Claim
31 words
An electronic device according to claim 7 wherein a length of the LDD region overlapping said gate electrode of said second TFT is in the range from 1 to 3 μm.
Claim 11
Dependent Claim
40 words
An electronic device according to claim 7 wherein an n-type impurity element is contained in the LDD region of said second TFT at a concentration 2 to 10 times higher than that of the LDD region of said first TFT.
Claim 12
Dependent Claim
31 words
An electronic device according to claim 7 wherein the LDD region of said second TFT contains an n-type impurity element at a concentration 2×10 16 to 5×10 19 atoms/cm 3 .
Claim 13
Dependent Claim
31 words
An electronic device according to claim 7 wherein the LDD region of said first TFT contains an n-type impurity element at a concentration 1×10 16 to 5×10 18 atoms/cm 3 .
Claim 14
Dependent Claim
52 words
An electronic device according to claim 7 wherein said electronic device is selected from the group consisting of a video camera, a digital camera, a goggle type display, a navigation systems, a sound reproduction device, a note type personal computer, a game machine, a portable information terminal, and an image projection device.
Claim 15
Dependent Claim
124 words
An electronic device having a pixel portion and a driving circuit portion formed on an insulating surface, said driving circuit portion comprising: at least one n-channel type TFT having an LDD (lightly-doped-drain) region partially or entirely overlapping a gate electrode with a gate insulation film interposed, and said pixel portion comprising: a pixel including a first TFT for switching, a second TFT for controlling current and an EL element connected to said second TFT; wherein an LDD region of said first TFT does not overlap a gate electrode of said first TFT with a gate insulation film interposed; and wherein an LDD region of said second TFT partially or entirely overlaps a gate electrode of said second TFT with a gate insulation film interposed.
Claim 16
Dependent Claim
124 words
An electronic device having a pixel portion and a driving circuit portion formed on an insulating surface, said driving circuit portion comprising: at least one n-channel type TFT having an LDD (lightly-doped-drain) region partially or entirely overlapping a gate electrode with a gate insulation film interposed, and said pixel portion comprising: a pixel including a first TFT for switching, a second TFT for controlling current and an EL element connected to said second TFT; wherein an LDD region of said first TFT does not overlap a gate electrode of said first TFT with a gate insulation film interposed; and wherein an LDD region of said second TFT partially or entirely overlaps a gate electrode of said second TFT with a gate insulation film interposed.
Claim 17
Dependent Claim
31 words
An electronic device according to claim 13 wherein a length of the LDD region overlapping the gate electrode of said second TFT is in the range from 1 to 3 μm.
Claim 18
Dependent Claim
40 words
An electronic device according to claim 13 wherein an n-type impurity element is contained in the LDD region of said second TFT at a concentration 2 to 10 times higher than that of the LDD region of said first TFT.
Claim 19
Dependent Claim
31 words
An electronic device according to claim 13 wherein the LDD region of said second TFT contains an n-type impurity element at a concentration 2×10 16 to 5×10 18 atoms/cm 3 .
Claim 20
Dependent Claim
31 words
An electronic device according to claim 13 wherein the LDD region of said first TFT contains an n-type impurity element at a concentration 1×10 16 to 5×10 18 atoms/cm 3 .
Claim 21
Dependent Claim
52 words
An electronic device according to claim 13 wherein said electronic device is selected from the group consisting of a video camera, a digital camera, a goggle type display, a navigation systems, a sound reproduction device, a note type personal computer, a game machine, a portable information terminal, and an image projection device.
Claim 22
Dependent Claim
122 words
An electronic device having a pixel portion and a driving circuit portion formed on an insulating surface, said driving circuit portion comprising: at least one n-channel type TFT having an LDD (lightly-doped-drain) region partially or entirely overlapping a gate electrode with a gate insulation film interposed, and said pixel portion comprising: a pixel including a first TFT for switching, a second TFT for controlling current and an EL element connected to said second TFT; wherein an LDD region of said first TFT overlaps a gate electrode of said first TFT with a gate insulation film interposed; and wherein an LDD region of said second TFT partially or entirely overlaps a gate electrode of said second TFT with a gate insulation film interposed.
Claim 23
Dependent Claim
122 words
An electronic device having a pixel portion and a driving circuit portion formed on an insulating surface, said driving circuit portion comprising: at least one n-channel type TFT having an LDD (lightly-doped-drain) region partially or entirely overlapping a gate electrode with a gate insulation film interposed, and said pixel portion comprising: a pixel including a first TFT for switching, a second TFT for controlling current and an EL element connected to said second TFT; wherein an LDD region of said first TFT overlaps a gate electrode of said first TFT with a gate insulation film interposed; and wherein an LDD region of said second TFT partially or entirely overlaps a gate electrode of said second TFT with a gate insulation film interposed.
Claim 24
Dependent Claim
31 words
An electronic device according to claim 19 wherein a length of the LDD region overlapping the gate electrode of said second TFT is in the range from 1 to 3 μm.
Claim 25
Dependent Claim
40 words
An electronic device according to claim 19 wherein an n-type impurity element is contained in the LDD region of said second TFT at a concentration 2 to 10 times higher than that of the LDD region of said first TFT.
Claim 26
Dependent Claim
31 words
An electronic device according to claim 19 wherein the LDD region of said second TFT contains an n-type impurity element at a concentration 2×10 16 to 5×10 19 atoms/cm 3 .
Claim 27
Dependent Claim
31 words
An electronic device according to claim 19 wherein the LDD region of said first TFT contains an n-type impurity element at a concentration 1×10 16 to 5×10 18 atoms/cm 3 .
Claim 28
Dependent Claim
52 words
An electronic device according to claim 19 wherein said electronic device is selected from the group consisting of a video camera, a digital camera, a goggle type display, a navigation systems, a sound reproduction device, a note type personal computer, a game machine, a portable information terminal, and an image projection device.
Claim 29
Dependent Claim
112 words
An electronic device having at least one pixel, said pixel comprising: a switching TFT; a current-control TFT connected to said switching TFT; an EL element connected to said current-control TFT, wherein an LDD (lightly-doped-drain) region formed in said switching TFT does not overlap a gate electrode of said switching TFT with a gate insulating film interposed, wherein an LDD region formed in said current-control TFT partially or entirely overlaps a gate electrode of said current-control TFT with a gate insulating film interposed, wherein an n-type impurity element is contained in the LDD region of said current-control TFT at a higher concentration higher than that of the LDD region of said switching TFT.
Claim 30
Dependent Claim
112 words
An electronic device having at least one pixel, said pixel comprising: a switching TFT; a current-control TFT connected to said switching TFT; an EL element connected to said current-control TFT, wherein an LDD (lightly-doped-drain) region formed in said switching TFT does not overlap a gate electrode of said switching TFT with a gate insulating film interposed, wherein an LDD region formed in said current-control TFT partially or entirely overlaps a gate electrode of said current-control TFT with a gate insulating film interposed, wherein an n-type impurity element is contained in the LDD region of said current-control TFT at a higher concentration higher than that of the LDD region of said switching TFT.
Claim 31
Dependent Claim
32 words
An electronic device according to claim 25 wherein the LDD region of said current-control TFT contains an n-type impurity element at a concentration of 2×10 16 to 5×10 19 atoms/cm 3 .
Claim 32
Dependent Claim
32 words
An electronic device according to claim 25 wherein the LDD region of said switching TFT contains an n-type impurity element at a concentration of 1×10 16 to 5×10 18 atoms/cm 3 .
Claim 33
Dependent Claim
52 words
An electronic device according to claim 25 wherein said electronic device is selected from the group consisting of a video camera, a digital camera, a goggle type display, a navigation systems, a sound reproduction device, a note type personal computer, a game machine, a portable information terminal, and an image projection device.
Claim 34
Dependent Claim
106 words
An electronic device having at least one pixel, said pixel comprising: a switching TFT; a current-control TFT connected to said switching TFT; an EL element connected to said current-control TFT; wherein an LDD (lightly-doped-drain) region formed in said switching TFT does not overlap a gate electrode of said switching TFT with a gate insulating film interposed, wherein an LDD region formed in said current-control TFT partially or entirely overlaps a gate electrode of said current-control TFT with a gate insulating film interposed, wherein a length of the LDD region overlapping the gate electrode of said current-control TFT is in the range from 1 to 3 μm.
Claim 35
Dependent Claim
106 words
An electronic device having at least one pixel, said pixel comprising: a switching TFT; a current-control TFT connected to said switching TFT; an EL element connected to said current-control TFT; wherein an LDD (lightly-doped-drain) region formed in said switching TFT does not overlap a gate electrode of said switching TFT with a gate insulating film interposed, wherein an LDD region formed in said current-control TFT partially or entirely overlaps a gate electrode of said current-control TFT with a gate insulating film interposed, wherein a length of the LDD region overlapping the gate electrode of said current-control TFT is in the range from 1 to 3 μm.
Claim 36
Dependent Claim
32 words
An electronic device according to claim 29 wherein the LDD region of said current-control TFT contains an n-type impurity element at a concentration of 2×10 16 to 5×10 19 atoms/cm 3 .
Claim 37
Dependent Claim
32 words
An electronic device according to claim 29 wherein the LDD region of said switching TFT contains an n-type impurity element at a concentration of 1×10 16 to 5×10 18 atoms/cm 3 .
Claim 38
Dependent Claim
52 words
An electronic device according to claim 29 wherein said electronic device is selected from the group consisting of a video camera, a digital camera, a goggle type display, a navigation systems, a sound reproduction device, a note type personal computer, a game machine, a portable information terminal, and an image projection device.
References Cited (Backward Citations)
US4996523A
Cited
WO1990013148A1
Cited
US5247190A
Cited
US5399502A
Cited
JPH1092576A
Cited
JPH0436971A
Cited
US6331723B1
Cited
JPH05102483A
Cited
US5828429A
Cited
US6023308A
Cited
US5323042A
Cited
US5302966A
Cited
US5499123A
Cited
US5594569A
Cited
US5643826A
Cited
JPH07130652A
Cited
US5923962A
Cited
US6198133B1
Cited
US5712495A
Cited
US5998841A
Cited
US5856689A
Cited
US5684365A
Cited
US5729308A
Cited
JPH08330602A
Cited
US5706064A
Cited
US6127210A
Cited
US6297862B1
Cited
US6160272A
Cited
JPH10270363A
Cited
US6310670B1
Cited
US6246179B1
Cited
US6281552B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2006-01-27 | 2006-07-29 | 2007-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2010-01-27 | 2010-07-29 | 2011-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2014-01-27 | 2014-07-29 | 2015-01-28 | $7700.00 | Window Closed / Lapsed |