JP4826685B2 - Electro-optical device and electronic apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electro-optical device and an electronic apparatus that prevent a substrate floating effect in an MIS transistor formed in a semiconductor layer on an insulator layer.
[0002]
[Prior art]
SOI (Silicon On Insulator) technology that forms a semiconductor layer consisting of a single crystal silicon layer on an insulator and forms a semiconductor device such as a transistor on the semiconductor layer,
It has advantages such as higher element speed, lower power consumption, and higher integration, and can be applied to electro-optical devices such as liquid crystal devices.
[0003]
By the way, in a general bulk semiconductor component, since the channel region of the MIS transistor can be held at a predetermined potential through the base substrate, the parasitic bipolar effect caused by the potential change of the channel portion, etc. Therefore, the electrical characteristics such as the breakdown voltage of the element are not deteriorated.
[0004]
However, in an SOI-structured MIS transistor, the channel region cannot be fixed at a predetermined potential as described above because the lower part of the channel is completely separated by the base insulating film, and the channel region is electrically floating. It becomes the state. At this time, surplus carriers generated by impact ionization due to collision between carriers accelerated by an electric field in the vicinity of the drain region and the crystal lattice accumulate in the lower portion of the channel. At this time, if excess carriers accumulate under the channel and the channel potential rises, the source / channel / drain NPN structure (in the case of the N channel type) operates as an apparent bipolar device, so the source of the device is caused by an abnormal current. -There was a problem that electrical characteristics deteriorated, such as the breakdown voltage between drains deteriorated. A series of phenomena caused by the channel portions being in an electrically floating state is called a substrate floating effect.
[0005]
In order to solve such problems, conventionally, a body contact region electrically connected to the channel region through a predetermined path is provided, and surplus carriers accumulated in the channel region are extracted from the body contact region. As a result, the substrate floating effect was suppressed.
[0006]
[Problems to be solved by the invention]
However, if a body contact region is provided in a MIS transistor used in a pixel region of an electro-optical device such as a liquid crystal device, it is difficult to increase the degree of integration of the pixel, particularly in the case of a transmissive type, the aperture ratio becomes small. There was a problem. Also, in the peripheral drive circuit other than the pixel region, if a body contact region is provided, integration becomes difficult. Furthermore, in an electro-optical device used in an electronic apparatus such as a projection display device, when intense light is incident on a channel region or LDD (Lightly Doped Drain) region of a pixel transistor, carriers are generated by photoexcitation and accumulated in the pixel. As a result of charge leakage from the capacitor, display unevenness such as flicker is caused.
[0007]
The present invention has been made in view of such circumstances, and an object thereof is an electro-optical device having a transistor that suppresses a substrate floating effect peculiar to SOI, particularly a projection display device in which light leakage is a problem. It is an object of the present invention to provide an electro-optical device that is optimal for the electronic apparatus and an electronic apparatus using the electro-optical device.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a semiconductor device formed in a semiconductor layer on an insulator layer as follows.
[0009]
  That is,The present inventionA plurality of scanning lines on a substrate constituted by a support substrate, a first insulator layer formed on the support substrate, and a semiconductor layer formed on the first insulator layer; A plurality of data lines intersecting the plurality of scanning lines, the scanning lines and the data linesAnd electricallyConnected pixel transistors and said pixel transistorsAnd electricallyAn electro-optical device having a connected pixel electrode and a peripheral circuit including a drive transistor for operating the pixel transistor, the channel region and the source region of the pixel transistor or the drive transistorA region having a defect density higher than that of the channel region is formed in the LDD region formed between the drain region and the drain region.It is characterized by that.
  The region having a high defect density is formed so as to be in contact with the channel region while being separated from the source region and the drain region.
[0010]
According to the configuration of the present invention, in a pixel or a driving transistor, a region having a defect density higher than that of a channel region functions as a carrier recombination center, thereby preventing excess carrier accumulation and suppressing a substrate floating effect. Can do. Further, even when light enters the LDD region that cannot be shielded by the gate electrode and carriers are generated by photoexcitation, leakage current can be prevented from flowing due to the recombination center.
[0011]
  This caseRelated to the reference inventionAccording to a second aspect of the present invention, a plurality of substrates are formed on a substrate including a support substrate, a first insulator layer formed on the support substrate, and a semiconductor layer formed on the first insulator layer. And a plurality of data lines intersecting the plurality of scanning lines, a pixel transistor connected to each of the scanning lines and the data lines, and a pixel electrode connected to the transistor. The defect density of at least one of the region including the junction portion between the channel region and the source region of the pixel transistor or the region including the junction portion between the channel region and the drain region is the channel density. It is characterized by being higher than the defect density of the region.
[0012]
  According to the configuration of the present invention, in the pixel transistor, a region having a defect density higher than that of the channel region functions as a carrier recombination center, thereby preventing the accumulation of surplus carriers and providing a substrate floating effect without taking a body contact. Thus, an electro-optical device having a high aperture ratio can be obtained. Further, even when light enters the LDD region that cannot be shielded by the gate electrode and carriers are generated by photoexcitation, leakage current can be prevented from flowing due to the recombination center.
  According to the reference invention of this caseAccording to a third aspect of the present invention, a plurality of substrates are formed on a substrate including a support substrate, a first insulator layer formed on the support substrate, and a semiconductor layer formed on the first insulator layer. A plurality of data lines intersecting the plurality of scanning lines, a pixel transistor connected to each scanning line and each data line, a pixel electrode connected to the transistor, and the pixel transistor An electro-optical device having a peripheral circuit including a driving transistor for operation, the region including a junction between a channel region and a source region of the pixel transistor or the driving transistor, or the channel region and the drain region The defect density of at least one of the regions including the junction portion is higher than the defect density of the channel region.
[0013]
According to the configuration of the present invention, in a pixel or a driving transistor, a region having a defect density higher than that of a channel region serves as a carrier recombination center, thereby preventing accumulation of surplus carriers and floating of a substrate without taking a body contact. The effect can be suppressed, and an electro-optical device with a high aperture ratio can be obtained. Further, even when light enters the LDD region that cannot be shielded by the gate electrode and carriers are generated by photoexcitation, leakage current can be prevented from flowing due to the recombination center. Also, the peripheral circuit can be laid out efficiently.
[0014]
  This caseRelated to the reference inventionAccording to the fourth aspect of the present invention, the substrate includes a support substrate, a first insulator layer formed on the support substrate, and a semiconductor layer formed on the first insulator layer. A plurality of scanning lines, a plurality of data lines intersecting the plurality of scanning lines, a pixel transistor connected to each scanning line and each data line, a pixel electrode connected to the pixel transistor, An electro-optical device having a peripheral circuit including a driving transistor for operating the pixel transistor, wherein the pixel transistor or a region closer to a channel than a junction portion between a channel region and a source region of the driving transistor; or Among the regions on the channel side of the junction between the channel region and the drain region, at least one region has a defect density higher than that of the channel region. It is characterized in that it comprises a driving transistor.
[0015]
  According to the configuration of the present invention, in a pixel or a driving transistor, a region having a defect density higher than that of a channel region functions as a carrier recombination center, thereby preventing accumulation of excess carriers and suppressing a substrate floating effect. it can. Further, even when light enters the LDD region that cannot be shielded by the gate electrode and carriers are generated by photoexcitation, leakage current can be prevented from flowing due to the recombination center.
  According to the reference invention of this caseAccording to the fifth aspect of the present invention, the substrate includes a support substrate, a first insulator layer formed on the support substrate, and a semiconductor layer formed on the first insulator layer. A plurality of scanning lines, a plurality of data lines intersecting the plurality of scanning lines, a pixel transistor connected to each scanning line and each data line, and a pixel electrode connected to the pixel transistor. An electro-optical device having at least a region on a channel side with respect to a junction portion between a channel region and a source region of the pixel transistor, or a region on a channel side with respect to a junction portion between the channel region and the drain region. The defect density of one region is higher than the defect density of the channel region.
[0016]
  According to the configuration of the present invention, in the pixel transistor, a region having a defect density higher than that of the channel region functions as a carrier recombination center, thereby preventing the accumulation of surplus carriers and providing a substrate floating effect without taking a body contact. In addition, an electro-optical device having a high aperture ratio can be obtained. Also, even if light is incident on the LDD region that cannot be shielded by the gate electrode and carriers are generated by photoexcitation, the recombination center can prevent leakage current from flowing, so there is no flicker or other high-quality electro-optics. A device is obtained.
  This caseRelated to the reference inventionAccording to a sixth aspect of the present invention, there is provided a substrate including a support substrate, a first insulator layer formed on the support substrate, and a semiconductor layer formed on the first insulator layer. A plurality of scanning lines; a plurality of data lines intersecting the plurality of scanning lines; a pixel transistor connected to each of the scanning lines and the data lines; a pixel electrode connected to the pixel transistor; An electro-optical device having a peripheral circuit including a driving transistor for operating a transistor, wherein the channel region is a region closer to a channel than a junction between a channel region and a source region of the pixel transistor or the driving transistor, or the channel region. The defect density of at least one of the regions closer to the channel than the junction between the drain region and the drain region is higher than the defect density of the channel region. There.
[0017]
According to the configuration of the present invention, in a pixel or a driving transistor, a region having a defect density higher than that of a channel region serves as a carrier recombination center, thereby preventing accumulation of surplus carriers and floating of a substrate without taking a body contact. The effect can be suppressed, and an electro-optical device with a high aperture ratio can be obtained. Further, even when light enters the LDD region that cannot be shielded by the gate electrode and carriers are generated by photoexcitation, leakage current can be prevented from flowing due to the recombination center. Also, the peripheral circuit can be laid out efficiently.
[0018]
In any one of the above inventions, it is desirable that the pixel transistors connected to the scanning lines and the data lines are P-channel type. According to this configuration, since the minority carriers of the pixel transistor are holes having a smaller impact ionization coefficient than electrons, the substrate floating effect is less likely to occur than when the N-channel type is used for the pixel transistor, and body contact is not required. An electro-optical device that can be driven at a higher voltage than the N-channel type and has a high aperture ratio is obtained. Furthermore, in the transistors connected to each scanning line and each data line, the region having a higher defect density than the channel region acts as a carrier recombination center, thereby preventing the accumulation of surplus carriers and further increasing the substrate floating effect. In order to suppress it, it is optimal for driving at a high voltage such as driving of liquid crystal. Further, even when light enters the LDD region that cannot be shielded by the gate electrode and carriers are generated by photoexcitation, leakage current can be prevented from flowing due to the recombination center. In such a configuration, at least a portion of the semiconductor layer formed on the first insulator layer in which the pixel transistors connected to the scanning lines and the data lines are formed. A structure with a film thickness of 100 nm or less is desirable. According to this configuration, the thickness of the semiconductor layer of at least the portion where the transistor connected to each scanning line and each data line is formed (that is, the portion irradiated with light) in the electro-optical device. Since it is thin, leakage current due to photoexcitation can be minimized.
[0019]
In any one of the above inventions, it is desirable that the defect in the region be introduced by Ar ion implantation. According to this configuration, defects introduced by Ar ion implantation serve as recombination centers.
[0020]
In any of the above inventions, it is desirable that the support substrate is single crystal silicon. According to this configuration, it can be applied to an electro-optical device such as a reflective liquid crystal device. Furthermore, there is an advantage that a bulk silicon device can be used as it is.
[0021]
In any one of the above inventions, it is preferable that the support substrate is quartz and the semiconductor layer formed on the first insulator layer is single crystal silicon. According to this configuration, since the support substrate is transparent, it can be applied to an electro-optical device such as a transmissive liquid crystal device. In addition, since the supporting substrate can be processed at a high temperature that cannot be performed with glass, a high-quality insulating film or the like can be obtained, and a highly reliable device can be provided. Furthermore, since the semiconductor layer is made of single crystal silicon, a high-quality and high-definition electro-optical device with an increased driving frequency can be obtained.
[0022]
In any one of the above inventions, it is desirable that the supporting substrate is quartz and the semiconductor layer formed on the first insulator layer is polycrystalline silicon. According to this configuration, since the support substrate is transparent, it can be applied to an electro-optical device such as a transmissive liquid crystal device. In addition, since the supporting substrate can be processed at a high temperature that cannot be performed with glass, a high-quality insulating film or the like can be obtained, and a highly reliable device can be provided. Furthermore, since the semiconductor layer is made of polycrystalline silicon, it can be easily formed on the substrate, and a high-definition electro-optical device can be easily obtained.
[0023]
In any one of the above inventions, the support substrate is preferably made of glass. According to this configuration, since the support substrate is an inexpensive transparent substrate, a transmissive electro-optical device such as a liquid crystal device can be provided at low cost.
[0024]
The electronic apparatus of the present invention includes a light source, the electro-optical device that performs modulation corresponding to image information when light emitted from the light source is incident, and a projection that projects light modulated by the electro-optical device. Means.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an electro-optical device according to an embodiment of the invention will be described with reference to the drawings.
[0026]
(Configuration of electro-optical device)
FIG. 1 is a diagram showing an equivalent circuit of an image forming area in a liquid crystal device as an electro-optical device according to an embodiment of the invention. FIG. 3 is a plan view showing an example of the structure of a transistor in the liquid crystal device, and FIG. 2 is a cross-sectional view taken along the line A-A ′.
[0027]
In FIG. 1, a plurality of pixels constituting the image display area of the liquid crystal device according to the present embodiment includes a plurality of pixel electrodes 9 a formed in a matrix and a pixel transistor 30 for controlling the pixel electrodes 9 a. Thus, the data line 6 a to which the image signal is supplied is electrically connected to the source of the pixel transistor 30. The image signals S1, S2,..., Sn written to the data lines 6a may be supplied line-sequentially in this order, or may be supplied for each group to a plurality of adjacent data lines 6a. Also good.
[0028]
Further, the scanning line 3a is electrically connected to the gate of the pixel transistor 30, and scanning signals G1, G2,..., Gm are applied to the scanning line 3a in a pulse-sequential manner in this order at a predetermined timing. It is configured as follows. The pixel electrode 9a is electrically connected to the drain of the pixel transistor 30, and the image signal S1, S2,... Sn supplied from the data line 6a is predetermined when the pixel transistor 30 is closed for a certain period. Write at the timing. Image signals S1, S2,..., Sn written to the liquid crystal via the pixel electrode 9a are held for a certain period with a counter electrode (described later) formed on a counter substrate (described later). . Here, in order to prevent the held image signal from leaking, a storage capacitor 70 is added in parallel to the liquid crystal capacitor formed between the pixel electrode 9a and the counter electrode. The storage capacitor 70 can improve the holding characteristics and realize a liquid crystal device with a high contrast ratio.
[0029]
Next, a cross-sectional structure of the transistor according to this embodiment will be described with reference to FIG. 2 shows only the transistor, and the pixel electrode 9a, the data line 6a, the storage capacitor 70, etc. in FIG. 1 are omitted.
[0030]
As shown in FIG. 2, a first insulator layer 2 is formed on the support substrate 1, and a P-channel transistor is formed on the first insulator layer 2. ing. Specifically, on the first insulator layer 2, an N− type channel region 3, a P + type source region 4 and a drain region 5 are provided in a predetermined region of the semiconductor layer. A MIS transistor is configured with a second insulator layer (gate insulating film) 6 and a gate electrode 7 formed thereon. Although not shown in this drawing, a light shielding layer is provided below the transistor and between the support substrate 1 and the first insulator layer 2. Specifically, the light shielding film is provided in a position in the image display region so as to cover the transistor when viewed from below.
[0031]
Here, the support substrate 1 may be any of single crystal silicon, a quartz substrate, and a glass substrate. If the support substrate 1 is single crystal silicon, it can be applied to a reflection type electro-optical device. In that case, the semiconductor layer is single crystal silicon. Further, if the support substrate 1 is a quartz substrate or a glass substrate, it can be applied to a transmissive electro-optical device. In that case, the semiconductor layer is either single crystal silicon or polycrystalline silicon.
[0032]
An interlayer insulating film 14 is formed so as to cover the semiconductor layer and the gate electrode 7. Although omitted in FIG. 2, the data line 6a in FIG. 1 is connected to the source region 4 through a contact hole formed in the interlayer insulating film 14, while the pixel electrode 9a in FIG. It is connected to the drain 5 through a contact hole formed in the interlayer insulating film 14.
[0033]
Further, like a normal MIS transistor, an LDD (Lightly Doped Drain) region 9 (a dotted line portion on the left side in FIG. 2) has a lower impurity concentration than the source region 4 between the channel region 3 and the source region 4. Similarly, between the channel region 3 and the drain region 5, the LDD region 9 (the dotted line portion on the right side in FIG. 2) has a lower impurity concentration than the drain region 5. It is formed as a P-type semiconductor layer. By having an LDD structure, the electric field distribution near the drain can be relaxed and impact ionization that causes the substrate floating effect can be reduced. Furthermore, since minority carriers in P-channel transistors are holes with a smaller impact ionization coefficient than electrons, substrate floating effects are less likely to occur than with N-channel transistors, and they are higher than N-channel transistors without body contact. It can be driven by voltage. Therefore, an electro-optical device having a high aperture ratio can be obtained by making the pixel transistor 30 a P-channel type.
[0034]
Further, Ar ions are implanted into a region 11 having a constant width including the junction between the channel region 3 and the source region 4 (the shaded portion on the left side in FIG. 2). It is high. Similarly, Ar ions are also implanted into a region 11 having a constant width including the junction between the channel region 3 and the drain region 5 (the shaded portion on the right side in FIG. 2). Higher. As shown in FIG. 3, these two regions 11 are provided along the gate electrode 7 over the entire region on the source region 4 side and the drain region 5 side, respectively.
[0035]
Here, Ar ions implanted into the region 11 introduce recombination centers of surplus carriers, and the substrate floating effect is further suppressed. In the pixel transistor 30 in which the source and the drain are switched, it is preferable that the region 11 is formed on both the source region 4 side and the drain region 5 side as shown in FIG. Similarly, the LDD regions 9 are preferably formed on both the source region 4 side and the drain region 5 side, respectively.
[0036]
In the present embodiment, element isolation is performed by mesa isolation, but any known substrate isolation method, for example, LOCOS (Local Oxidation of Silicon) isolation or trench may be used.
[0037]
The effect of improving the breakdown voltage of the transistor of this embodiment is not limited to the P-channel type, and the N-channel type may be used because the N-channel type also has the effect.
[0038]
Furthermore, the transistor of this embodiment is effective for both a partially depleted type and a fully depleted type. In the case of the partial depletion type, the thickness of the semiconductor layer in the portion where the channel region 3 is formed is preferably 100 nm to 300 nm, and in the case of the full depletion type, the thickness of the portion where the channel region 3 is formed The thickness of the semiconductor layer is preferably 30 nm to 100 nm (typically about 50 nm).
[0039]
Note that in the case where the pixel transistor portion can be almost completely shielded from light, a partial depletion type in which the semiconductor layer of the pixel transistor portion is thick can be applied within a range in which a leak current due to photoexcitation can be allowed.
[0040]
Further, when the light shielding is not complete and stray light enters, if the film thickness of the semiconductor layer in the portion where the channel region 3 is formed is 100 nm or less in the pixel transistor 30 irradiated with light, the leakage current due to photoexcitation is reduced. It is suppressed. Since the number of carriers generated by photoexcitation is proportional to the film thickness of the semiconductor layer, the smaller the film thickness, the lower the light leakage current. However, if the film thickness is too thin, it becomes difficult to control the threshold voltage of the transistor. Is preferred. Further, in the case where an increase in sheet resistance of the source / drain becomes a problem due to the reduced thickness of the semiconductor layer, the resistance can be reduced by silicidizing the source / drain.
[0041]
Furthermore, in both the partially depleted transistor and the fully depleted transistor, even if light enters the LDD region that cannot be shielded by the gate electrode and carriers are generated by photoexcitation, it prevents leakage current from flowing due to the recombination center. it can.
[0042]
In addition, when a peripheral circuit including a driving transistor for operating the pixel transistor 30 is provided around the image display area, the thickness of only the semiconductor layer of the pixel transistor 30 in the image display area in the image display area that requires light leakage countermeasures is 100 nm or less. The film thickness of the semiconductor layer applied to the driving transistor constituting the peripheral circuit may be 100 nm or less or 100 nm or more.
[0043]
In the present embodiment, it may be combined with a body contact. That is, by further providing a body contact region that is electrically connected to the channel region through a predetermined path, it is possible to further suppress the substrate floating effect by extracting excess carriers accumulated in the channel region from the body contact region. Is possible.
[0044]
(Modification 1 of this embodiment)
FIG. 4 shows a first modification of the above-described embodiment, and only differences from the above-described embodiment will be described, and descriptions of common parts will be omitted.
[0045]
As shown in FIG. 4, in Modification 1, the LDD region 9 (dotted line portion in FIG. 4) and the region 11 having a defect density higher than the channel region 3 (shaded portion in FIG. 4) overlap. . That is, in the first modification, Ar ions are implanted into the entire LDD region 9. According to such a configuration, the resistance of the source region 4 and the drain region 5 does not increase.
[0046]
(Modification 2 of this embodiment)
FIG. 5 shows a second modification of the above-described embodiment, and only the differences from the above-described embodiment will be described, and description of common parts will be omitted.
As shown in FIG. 5, in Modification 2, the LDD region 9, the source region 4 or the drain region 5, and the region 11 overlap. That is, Ar ions are implanted throughout the LDD region 9 and the source region 4 or the drain region 5.
According to the second modification, there is an advantage that a mask for implanting impurities into the LDD region 9 and a mask for implanting Ar ions into the region region 11 can be used together. That is, Ar ions can be implanted into the region 11 in the same step as the step of implanting impurities into the LDD region 9, and the number of steps does not increase. Further, when Ar ions are implanted into the region 11 after the activation of the source region 4 and the drain region 5, a mask for forming the LDD region 9 can be used.
[0047]
(Modification 3 of this embodiment)
FIG. 6 shows a third modification of the above-described embodiment, and only the differences from the above-described embodiment will be described, and description of common parts will be omitted.
[0048]
As shown in FIG. 6, in the third modification, the region 11 is formed only in the channel region 3. That is, the LDD region 9 (dotted line portion in FIG. 6), the source region 4 and the drain region 5 are not implanted with Ar ions.
[0049]
According to such a configuration, the leakage current due to the defect can be minimized.
[0050]
(Other)
In the present invention, in a transistor in which the source region and the drain region are not interchanged, a region 11 having a defect density higher than that of the channel region 3 may be provided only in one of the source region and the drain region. The LDD region 9 may be provided only on the drain side. In the present invention, the method of forming the region 11 having a defect density higher than that of the channel region 3 is not limited to Ar ion implantation. Ions such as silicon, oxygen, carbon, and nitrogen may be implanted.
[0051]
(Overall configuration of liquid crystal device)
Next, the overall configuration of the liquid crystal device according to the embodiment will be described with reference to FIGS. 7 and 8. 7 is a plan view of the element substrate 10 on which the transistor is formed as viewed from the side of the counter substrate 20 together with other components formed therein. FIG. 8 shows the element substrate 10 including the counter substrate 20. It is HH 'sectional drawing of FIG.
[0052]
As shown in FIG. 7, the counter substrate 20 is provided with a third light shielding film 53 as a frame made of the same or different material as the second light shielding film 23 in parallel with the inside of the sealing material 52. The second light-shielding film 23 faces the pixel electrode 9a in order to prevent incident light from the counter substrate 20 from entering the pixel transistor 30 and preventing color mixture between pixels. It is provided in an area other than the area.
[0053]
On the other hand, in the element substrate 10, a data line driving circuit 101 and an external circuit connection terminal 102 are provided along one side of the element substrate 10 in a region outside the sealing material 52. It is provided along two sides adjacent to one side. Needless to say, if the delay of the scanning signal supplied to the scanning line 3a is not a problem, the scanning line driving circuit 104 may be provided on only one side. Further, the data line driving circuit 101 may be arranged on both sides along the side of the image display area. For example, the odd-numbered data lines 6a are supplied with image signals from a data line driving circuit arranged along one side of the image display area, and the even-numbered data lines 6a are provided on the opposite side of the image display area. An image signal may be supplied from a data line driving circuit arranged along the line. If the data lines 6a are driven in a comb-like shape in this way, the area occupied by the data line driving circuit can be expanded, so that a complicated circuit can be configured. Further, on the remaining side of the element substrate 10, a plurality of wirings 105 are provided for connecting between the scanning line driving circuits 104 provided on both sides of the image display area. Further, at least one corner portion of the counter substrate 20 is provided with a vertical conductive material 106 for establishing electrical continuity between the element substrate 10 and the counter substrate 20. As shown in FIG. 8, the counter substrate 20 having substantially the same outline as the sealing material 52 is fixed to the element substrate 10 by the sealing material 52.
[0054]
On the element substrate 10 of such a liquid crystal device, an inspection circuit or the like for inspecting the quality, defects, etc. of the liquid crystal device during manufacturing or at the time of shipment is further provided, and the data line driving circuit 101 and the scanning line driving are provided. It is formed as a peripheral circuit together with the circuit 104.
[0055]
Further, instead of providing the data line driving circuit 101 and the scanning line driving circuit 104 on the element substrate 10, for example, a driving LSI mounted on a TAB (tape automated bonding substrate) is provided on the periphery of the element substrate 10. You may make it connect electrically and mechanically through the provided anisotropic conductive film.
[0056]
Further, for example, a TN (twisted nematic) mode, an STN (super TN) mode, and a D-STN (dual scan) are respectively provided on the side on which the projection light of the counter substrate 20 enters and the side on which the outgoing light of the element substrate 10 exits. -A polarizing film, a retardation film, a polarizing means, etc. are arranged in a predetermined direction according to the operation mode such as the -STN mode or the normally white mode / normally black mode.
[0057]
When the liquid crystal device described above is applied to, for example, a color liquid crystal projector (projection display device), three liquid crystal devices are used for RGB light valves. In this case, the light of each color separated through the dichroic mirror for RGB color separation is respectively incident on each panel, and then synthesized and projected. Therefore, in this case, the counter substrate 20 is not provided with a color filter as in the embodiment.
[0058]
However, when the liquid crystal device according to the embodiment is applied as a color liquid crystal device such as a direct-viewing type or a reflection type color liquid crystal television other than the liquid crystal projector, the second light shielding film 23 is a region facing the pixel electrode 9a. The RGB color filter may be formed on the counter substrate 20 together with the protective film in a region where the film is not formed.
[0059]
On the other hand, when the liquid crystal device in the embodiment is applied to a light valve of a liquid crystal projector, microlenses may be formed on the counter substrate 20 so as to correspond to one pixel. In this way, a bright liquid crystal device can be realized by improving the collection efficiency of incident light. Furthermore, a dichroic filter that produces RGB colors by using interference of light may be formed by depositing several layers of interference layers having different refractive indexes on the counter substrate 20. According to this counter substrate with a dichroic filter, a brighter color liquid crystal device can be realized.
[0060]
(Electronics)
Next, as an example of an electronic apparatus using the liquid crystal device, a configuration of a projection display device will be described with reference to FIG. FIG. 9 is a diagram showing a schematic configuration of an optical system of a projection type liquid crystal device 1100 prepared by using three liquid crystal devices as described above and used as RGB liquid crystal devices 962R, 962G, and 962B, respectively. A light source device 920 and a uniform illumination optical system 923 are employed in the optical system of the projection display device 1100 of this example. The projection display apparatus 1100 includes a color separation optical system 924 that separates the light beam W emitted from the uniform illumination optical system 923 into red (R), green (G), and blue (B), and each color light beam R, Light valves 925R, 925G, and 925B that modulate G and B, respectively, a color combining prism 910 that recombines the modulated color light flux, and a projection unit that enlarges and projects the combined light flux on the surface of the projection surface 100 Projection lens unit 906 is provided. Further, a light guide system 927 for guiding the blue light beam B to the corresponding light valve 925B is also provided.
[0061]
The uniform illumination optical system 923 includes two lens plates 921 and 922 and a reflection mirror 931, and the two lens plates 921 and 922 are arranged to be orthogonal to each other with the reflection mirror 931 interposed therebetween. The two lens plates 921 and 922 of the uniform illumination optical system 923 each include a plurality of rectangular lenses arranged in a matrix. The light beam emitted from the light source device 920 is divided into a plurality of partial light beams by the rectangular lens of the first lens plate 921. These partial light beams are superimposed in the vicinity of the three light valves 925R, 925G, and 925B by the rectangular lens of the second lens plate 922. Therefore, by using the uniform illumination optical system 923, even when the light source device 920 has a non-uniform illuminance distribution within the cross section of the emitted light beam, the three light valves 925R, 925G, and 925B can be uniformly illuminated. It can be illuminated.
[0062]
Each color separation optical system 924 includes a blue-green reflecting dichroic mirror 941, a green reflecting dichroic mirror 942, and a reflecting mirror 943. First, in the blue-green reflecting dichroic mirror 941, the blue light beam B and the green light beam G included in the light beam W are reflected at right angles and travel toward the green reflecting dichroic mirror 942. On the other hand, the red light beam R passes through the blue-green reflecting dichroic mirror 941, is reflected at a right angle by the rear reflecting mirror 943, and is emitted from the emission unit 944 of the red light beam R toward the color synthesis optical system.
[0063]
Next, out of the blue light beam B and the green light beam G reflected by the blue-green reflecting dichroic mirror 941, only the green light beam G is reflected at a right angle by the green reflecting dichroic mirror 942, and the color is emitted from the emitting portion 945 of the green light beam G. The light is emitted to the side of the combining optical system. Further, the blue light beam B that has passed through the green reflecting dichroic mirror 942 is emitted from the light beam emitting portion 946 to the light guide system 927 side. In this example, the distances from the emission part of the light beam W of the uniform illumination optical element to the emission parts 944, 945, and 946 of each color light beam in the color separation optical system 924 are set to be substantially equal to each other.
[0064]
Condensing lenses 951 and 952 are arranged on the emission side of the emission part 944 for the red light beam R and the emission side of the emission part 945 for the green light beam G by the color separation optical system 924, respectively. Therefore, the red light beam R and the green light beam G emitted from each of the emission units are incident on these condenser lenses 951 and 952 and are collimated.
[0065]
The collimated red light beam R and green light beam G are incident on the light valves 925R and 925G and modulated, and image information corresponding to each color light is added. That is, these liquid crystal devices are subjected to switching control in accordance with image information by a driving unit (not shown), thereby modulating each color light passing therethrough.
[0066]
On the other hand, the blue light beam B is guided to the corresponding light valve 925B via the light guide system 927, where it is similarly modulated according to the image information. The light valves 925R, 925G, and 925B in this example further include incident-side polarization means 960R, 960G, and 960B, emission-side polarization means 961R, 961G, and 961B, and liquid crystal devices 962R and 962G disposed therebetween. , 962B.
[0067]
By the way, the light guide system 927 is disposed between the condensing lens 954, the incident-side reflecting mirror 971, the emitting-side reflecting mirror 972, and the reflecting mirrors disposed on the emitting side of the emitting portion 946 of the blue light beam B. The intermediate lens 973 and the condensing lens 953 disposed on the front side of the light valve 925B. The blue light beam B emitted from the emission unit 946 is guided to the liquid crystal device 962B via the light guide system 927 and modulated. The optical path length of each color light beam, that is, the distance from the emission part of the light beam W to each of the liquid crystal devices 962R, 962G, 962B, the blue light beam B is the longest, and therefore the light amount loss of the blue light beam is the largest. However, the light loss can be suppressed by interposing the light guide system 927.
[0068]
The color light beams R, G, and B modulated through the light valves 925R, 925G, and 925B are incident on the color synthesis prism 910 and synthesized there. Then, the light synthesized by the color synthesis prism 910 is enlarged and projected onto the surface of the projection surface 100 at a predetermined position via the projection lens unit 906.
[0069]
In this example, since the liquid crystal devices 962R, 962G, and 962B are provided with a light shielding layer on the lower side of the transistor, the liquid crystal devices 962R, 962G, and 962B depend on the projection optical system in the liquid crystal projector based on the projection light from the liquid crystal devices 962R, 962G, and 962B. Reflected light, reflected light from the surface of the element substrate when the projected light passes through, a part of the projected light that penetrates the projection optical system after being emitted from another liquid crystal device, etc. are returned to the element substrate side. Even if the light is incident on the pixel transistor, light can be sufficiently shielded from the channel of the pixel transistor.
[0070]
For this reason, even if the color combining prism 910 suitable for miniaturization is used, a film for preventing return light is separately disposed between the liquid crystal devices 962R, 962G, 962B and the color combining prism 910, or polarizing means. Therefore, it is not necessary to perform the light prevention process, and this is very advantageous in reducing the size and simplification of the configuration.
[0071]
In this example, since the influence of the return light on the channel region of the transistor can be suppressed, the polarizing means 961R, 961G, and 961B subjected to the return light prevention process directly on the liquid crystal device need not be attached. Therefore, as shown in FIG. 9, the polarizing means is formed away from the liquid crystal device. More specifically, one polarizing means 961R, 961G, 961B is attached to the color combining prism 910, and the other polarizing means 960R, 960G and 960B can be attached to the condenser lenses 951, 952, and 953. As described above, when the polarization unit is attached to the color synthesis prism 910 or the condenser lenses 951, 952, and 953, heat of the polarization unit is absorbed by the color synthesis prism 910 or the condenser lenses 951, 952, and 953. The temperature rise of the liquid crystal device can be suppressed, and the malfunction can be prevented beforehand.
[0072]
Although not shown, an air layer is formed between the liquid crystal device and the polarizing means by forming the liquid crystal device and the polarizing means apart from each other. By providing cooling means here and sending cool air or other blast between the liquid crystal device and the polarizing means, the temperature rise of the liquid crystal device is further suppressed, and the malfunction due to the temperature rise of the liquid crystal device is more reliably prevented. It becomes possible to do.
[0073]
In the above description, the electro-optical device is described as a liquid crystal device. However, the present invention is not limited to this, and the present invention can also be applied to various electro-optical devices such as electroluminescence and a plasma display. is there.
[0074]
【The invention's effect】
As described above, according to the present invention, in a transistor, a region having a defect density higher than that of a channel region serves as a carrier recombination center, thereby preventing accumulation of surplus carriers and suppressing a substrate floating effect. Is possible. In addition, even when light is incident on the transistor, the recombination center works to prevent light leakage current, so that an electro-optical device with high display quality can be provided.
[Brief description of the drawings]
FIG. 1 is an equivalent circuit illustrating a configuration of an image forming region in a liquid crystal device according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view illustrating a structure of a transistor in the liquid crystal device.
FIG. 3 is a plan view illustrating a configuration of a transistor in the liquid crystal device.
FIG. 4 is a cross-sectional view showing a configuration of a transistor in Modification 1 of the embodiment.
FIG. 5 is a cross-sectional view showing a configuration of a transistor in Modification 2 of the embodiment.
FIG. 6 is a cross-sectional view showing a configuration of a transistor in Modification 3 of the embodiment.
FIG. 7 is a plan view showing a configuration of the liquid crystal device.
FIG. 8 is a cross-sectional view taken along the line H-H ′ of FIG.
FIG. 9 is a plan view showing a configuration of a projection display device which is an example of an electronic apparatus using the liquid crystal device.
[Explanation of symbols]
1 ... Support substrate
2 ... 1st insulator layer
3 Channel region
4 ... Source area
5 ... Drain region
6 ... Second insulator layer (gate insulating film)
7 ... Gate electrode
9 ... LDD area
10: Element substrate
11 ... Area
14 ... Interlayer insulating film
20 ... Counter substrate
52 ... Sealing material
53. Picture frame
100 ... Liquid crystal device
101: Data line driving circuit
102: External circuit connection terminal
104: Scanning line driving circuit
106: vertical conduction material

Claims (10)

On a substrate constituted by a support substrate, a first insulator layer formed on the support substrate, and a semiconductor layer formed on the first insulator layer,
A plurality of scan lines;
A plurality of data lines intersecting the plurality of scanning lines;
A pixel transistor electrically connected to each scanning line and each data line;
A pixel electrode electrically connected to the pixel transistor;
An electro-optical device having a peripheral circuit including a driving transistor for operating the pixel transistor,
An electro-optical device characterized in that a region having a defect density higher than that of the channel region is formed in an LDD region formed between a channel region of the pixel transistor or the driving transistor and a source region and a drain region, respectively. . The electro-optical device according to claim 1.
The electro-optical device, wherein the region having a high defect density is formed so as to be in contact with the channel region while being separated from the source region and the drain region. The electro-optical device according to claim 1 or 2 ,
The electro-optical device, wherein the pixel transistors connected to the scanning lines and the data lines are P-channel type. The electro-optical device according to claim 3 .
An electro-optical device , wherein a film thickness of at least a portion where the pixel transistor is formed in the semiconductor layer formed on the first insulator layer is 100 nm or less. The electro-optical device according to any one of claims 1 to 4 ,
The electro-optical device is characterized in that the region having a high defect density is formed by Ar ion implantation. The electro-optical device according to any one of claims 1 to 5 ,
An electro-optical device, wherein the support substrate is single crystal silicon. The electro-optical device according to any one of claims 1 to 5 ,
An electro-optical device, wherein the support substrate is quartz, and the semiconductor layer formed on the first insulator layer is single crystal silicon. The electro-optical device according to any one of claims 1 to 5 ,
An electro-optical device, wherein the support substrate is quartz, and the semiconductor layer formed on the first insulator layer is polycrystalline silicon. The electro-optical device according to any one of claims 1 to 5 ,
The electro-optical device, wherein the support substrate is glass. A light source;
The electro-optical device according to any one of claims 1 to 9 , wherein light emitted from the light source is incident to perform modulation corresponding to image information;
An electronic apparatus comprising: projection means for projecting light modulated by the electro-optical device.

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