JPH1054997A - Active matrix liquid crystal display device, its manufacture and device used for its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an active matrix liquid crystal display device, its manufacture and a device used for its manufacture formed while directly answering to a change in impurity concentration and the change in an irradiation distribution caused by that an irradiation state is changed every hour when a thin film transistor incorporated in the active matrix liquid crystal display device is formed on a large-sized glass substrate. SOLUTION: The formation of the thin film transistor in the active matrix liquid crystal display device is constituted so that by controlling a beam current based on the impurity concentration data measured beforehand by a mass spectrometer 16 without that an ion beam taken out from an ion source 9 is mass separated and the beam distribution data measured beforehand by a multi-point beam ammeter 17, a total beam irradiation amount is controlled, and a specimen in a processing room is irradiated by the ion beam.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a non-mass separation type ion beam irradiation apparatus, a method for manufacturing a thin film transistor for driving an active matrix type liquid crystal display device manufactured by using the ion beam irradiation apparatus, and using the ion beam irradiation apparatus. And an active matrix type liquid crystal display device formed according to the above-mentioned manufacturing method.

[0002]

2. Description of the Related Art In a display device using liquid crystal, an active matrix type liquid crystal display device having a large screen and high definition has been actively developed. In particular, by using a thin film transistor for driving each pixel, high contrast display without crosstalk can be achieved.

FIGS. 3A to 3C are process cross-sectional views showing a process for manufacturing a conventional thin film transistor. In FIG. 3, 1 is a gate electrode, 2 is a gate insulating film, 3 is a silicon semiconductor layer, 4 is an insulating thin film, 5 is phosphorus ions, 6 is an injection layer, 7 is a source / drain. Electrodes. As shown in FIG. 3A, a gate insulating film 2 made of an insulating film such as silicon nitride is deposited by a CVD method or the like on a gate electrode 1 obtained by patterning a metal thin film by photolithography. Subsequently, the silicon semiconductor layer 3 and the insulating thin film 4 are patterned after being deposited by a CVD method or the like. After that, FIG.
As shown in (b), phosphorus ions 5 are used as impurity ions.
Is implanted by an ion implantation method to form an implantation layer 6. Further, by forming a source / drain electrode 7 on the injection layer 6, a thin film transistor as shown in FIG.

In order to form a thin film transistor on a large glass substrate, a method of forming an impurity-implanted layer by a non-mass separation method without mass separation of implanted ions is used instead of a conventional method of mass separation. However, it is advantageous in that the size of the apparatus can be reduced and the injection time can be shortened.

FIG. 4 is a schematic plan view showing an example of a manufacturing apparatus used for a conventional ion doping method. In FIG. 4, 5 is a phosphorus ion, 8 is an impurity ion generating gas, 9 is an ion source, 10 is an electrode, 11 is a sample stage, 12 is a glass substrate, and 13 is a beam for measuring a current value of a beam at the time of ion beam irradiation. An ammeter, 14 is an integrating ammeter, and 15 is an ion source power switch. One end of the ion source power switch is connected to an ion source power supply (not shown). In the manufacturing apparatus, after the gas 8 that generates impurity ions is introduced into the ion source 9, the impurity ion generating gas 8 is ionized by a high frequency sputtering method (RF sputtering method), an ion bucket method, or the like. Further, impurity ions accelerated by the group of electrodes 10 including acceleration electrodes and the like are injected into a large-sized glass substrate 12 on the sample stage 11.

The ion implantation is performed as follows. That is, the number of irradiation ions is counted by the integrating ammeter 14 based on the current value measured by the beam ammeter 13, and the ion source power switch 15 is turned on when the total beam irradiation amount indicating the total irradiation amount of the ion beam is reached. Turn off and end the irradiation. At this time, the number of irradiation ions is measured based on data indicating the relationship between the number of irradiation ions and the integrated current value, which is measured in advance.

In the ion beam irradiation by the non-mass separation method, ions other than the desired impurity ions are also irradiated. Therefore, in order to know the impurity concentration at that time, as shown in FIG. Used. FIG. 5 is a schematic plan view showing the configuration of a manufacturing apparatus used for a conventional ion doping method. In FIG. 5, reference numeral 16 denotes a mass spectrometer, 17 denotes a multipoint beam ammeter for measuring the current value of the ion beam at a plurality of measurement positions, and the other symbols are those in FIG.
The same parts as those shown in FIGS. Since the manufacturing apparatus used in the conventional ion doping method as shown in FIG. 5 has a wide irradiation area, the distribution of beam intensity is measured using the multipoint beam ammeter 17. The user of the apparatus responds to changes in the irradiation state and changes in the impurity concentration at the time of gas switching by calculating the total injection amount from the impurity concentration data of the mass spectrometer. Similarly, the total injection amount is determined from the difference between the average value of the beam current measured by the multipoint beam ammeter and the beam current value measured during actual irradiation.

[0008]

However, in the above-described method of calculating the total injection amount from the impurity concentration data of the mass spectrometer and responding thereto, the operation and calculation by the apparatus user when determining the total injection amount are performed. In addition to the complicated work, there is a problem that it is not possible to immediately respond to a change in the impurity concentration and a change in the dose distribution due to a change in the state of the manufacturing apparatus that changes every moment.

According to the present invention, when a thin film transistor included in an active matrix type liquid crystal display device is formed on a large glass substrate, the change in the impurity concentration and the change in the dose distribution caused by the instantaneous change of the irradiation state are considered. It is an object of the present invention to provide an active matrix type liquid crystal display device which is formed while taking immediate action, a method for manufacturing the same, and a device used for the method.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an ion beam irradiation apparatus without mass separation, in which impurity concentration data obtained from a mass analyzer and beam analysis data obtained from a multipoint beam ammeter are used. Based on this, a manufacturing apparatus having means for controlling the total beam irradiation amount is provided.

That is, according to the manufacturing method of the present invention, when a thin film transistor including a pixel and a source / drain contact region is formed on a large-sized glass substrate, at least one of a plurality of thin film layers constituting the thin film transistor is formed. A method of manufacturing a thin film transistor of an active matrix type liquid crystal display device in which an impurity is implanted by irradiating an ion beam extracted from an ion source with a beam based on pre-measured impurity concentration data and pre-measured beam distribution data. By controlling the current, the total beam irradiation amount is controlled, and the sample in the processing chamber is irradiated with the ion beam without performing mass separation.

Further, the total beam irradiation amount is controlled based on a product obtained by multiplying a proportional constant obtained as a result of comparing the impurity concentration data with the beam distribution data by a desired impurity irradiation amount. Alternatively, it is preferable in that an error in the injection amount between different lots can be prevented due to a change in the impurity data or the beam distribution data over a large span such as when the state of the manufacturing apparatus changes.

In general, the ion source also contains unnecessary impurity ions other than the desired impurity ions. In this specification, the irradiation amount excluding the irradiation amount relating to the unnecessary impurity ions in the total beam irradiation amount is referred to as an impurity irradiation amount. Further, the state of the manufacturing apparatus is
For example, the temperature in the manufacturing apparatus or the function of a device constituting the manufacturing apparatus is reduced.

Further, the total beam irradiation amount is controlled based on a quotient obtained by dividing a proportional constant obtained as a result of comparing the impurity concentration data with the beam distribution data by a desired impurity irradiation amount. Alternatively, it is preferable in that an error in the injection amount between different lots can be prevented due to a change in the impurity data or the beam distribution data over a large span such as when the state of the manufacturing apparatus changes.

Further, the total beam irradiation amount is controlled in accordance with the impurity implantation amount counted based on the sum of the beam currents obtained as a result of integrating the beam currents,
Due to a small change in the beam current in a small span from the time when the irradiation of the ion beam to one glass substrate ends to the time when the irradiation of the ion beam to the next glass substrate starts, the one glass substrate and the next This is preferable in that an injection amount error can be prevented from occurring between the glass substrate and the glass substrate.

An ion beam irradiating apparatus according to the present invention is an ion beam irradiating apparatus used for manufacturing a thin film transistor of an active matrix type liquid crystal display device, wherein the ion beam irradiating apparatus measures a current of an ion beam; A mass analyzer for measuring the impurity concentration, a multi-point beam ammeter for measuring the distribution of the ion beam at a plurality of measurement points, and a control means for controlling the total beam irradiation amount based on the impurity concentration and the distribution data of the ion beam. It is characterized by comprising.

Further, the control means for controlling the total beam irradiation amount further comprises means for comparing impurity concentration data obtained from the mass analyzer with beam distribution data obtained from the multipoint beam ammeter. Is preferable in that the amount of impurity irradiation can be accurately controlled.

Further, it is preferable that the control means is an integrating ammeter since the total beam irradiation amount can be controlled with good reproducibility.

An active matrix type liquid crystal display device according to the present invention is an active matrix type liquid crystal display device in which a thin film transistor including a pixel and a source / drain contact region is formed on a large glass substrate, and is drawn from an ion source. The total beam is controlled by controlling the beam current based on the impurity concentration data previously measured by the mass analyzer and the beam analysis data previously measured by the multipoint beam ammeter without performing the mass separation of the ion beam. The source and drain contact regions are formed by controlling the irradiation amount and irradiating the ion beam.

As described above, according to the present invention, a change in the state of the manufacturing apparatus and a change in the impurity concentration at the time of gas switching are prevented.
Control of the dose of impurity irradiation can be performed accurately and quickly.

[0021]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic plan explanatory view showing the configuration of a manufacturing apparatus when setting an injection amount in an ion beam irradiation apparatus as a manufacturing apparatus according to an embodiment of the present invention. In FIG. 1, 5 is a phosphorus ion, 8 is an impurity ion generating gas, 9 is an ion source, 10 is an electrode, 11 is a sample stage, 12 is a glass substrate, 13 is a beam ammeter, 14 is an integrating ammeter, and 15 is an ion source. A power switch, 16 is a mass analyzer, 17 is a multipoint beam ammeter, 18 and 21 are counting circuits, 19 is an injection controller, and 20 and 22 are calculators.

In the present embodiment, a DC ammeter having a measurement range of 1 pA to 100 mA is used as the beam ammeter. Further, an accumulative ammeter having a function of automatically switching the current and the frequency to desired values is used. The multipoint beam ammeter according to the present invention can monitor about 100 ion beams, and is included in a circular area having a diameter of about 800 mm to be irradiated with an ion beam in an ion beam irradiation apparatus. For a rectangular area in contact with the circumference of a circle, for example, an area of 565 mm × 565 mm.
About 0 points can be monitored. As the mass spectrometer, a magnetic field control type having a resolution of about 100 is used. The implantation controller controls the total implantation amount of impurity ions, and includes an input / output device, a display device,
It is composed of a communication device and the like. Next, the counting circuit 18 has a function of analyzing the ion species, and comprises a circuit for outputting a desired electric signal based on the mass of the ion species obtained using the magnetic field of the mass analyzer. Similarly, the counting circuit 21
It has a function of switching points monitored by the multipoint beam ammeter 17 and includes a circuit for outputting a desired electric signal based on the sum of the beam currents of the monitored points. Further, the computer 20 has a function of comparing and calculating the signal output from the injection controller and the electric signal output from the counting circuit 21, and includes a comparison circuit and a difference circuit. Similarly, calculator 22 is an infusion controller,
It has a function of comparing and calculating each signal of the computer 20 and the counting circuit 21, and includes an input / output device, a display device, a storage device and the like.

In the present invention, the proportionality constant obtained as a result of comparing the impurity concentration data obtained from the mass analyzer 16 with the beam distribution data based on the beam current average value at each point obtained from the multipoint beam ammeter 17. Based on the product of the desired impurity dose corresponding to the impurity implantation dose,
The impurity implantation amount may be controlled by controlling the total beam irradiation amount corresponding to the final total implantation amount, and a proportional constant obtained by comparing the impurity concentration data with the beam distribution data may be a desired constant. The injection amount of the impurity may be controlled by controlling the total beam irradiation amount based on the quotient divided by the impurity irradiation amount, and is counted based on the sum of the beam currents obtained as a result of integrating the beam currents. The injection amount of the impurity may be controlled by controlling the total beam irradiation amount according to the injection amount of the impurity.

Next, a method of controlling impurity implantation using data obtained from these ammeters and counting circuits will be described with reference to the impurity implantation amount counted based on the total beam current obtained as a result of integrating the beam current. The case where the amount of impurity implantation is controlled by controlling the total beam irradiation amount correspondingly will be described in detail as an example. Mass spectrometer 1
Data obtained from 6 is a current value. From the current value, a desired impurity concentration A in the total beam current is obtained by the counting circuit 18. When the impurity ion generating gas is, for example, PH ₃ gas, the impurities are phosphorus ions, hydrogenated phosphorus ions, or the like. These impurity concentrations are usually less than 100%. The necessary amount B of impurities to be implanted by the implantation controller 19, for example, in the case of PH ₃ gas, the amount of phosphorus ions is input. For example, when the impurities are phosphorus ions, the impurity concentration A is 10 to 90% of the total ion implantation amount, and the impurity implantation amount B is 1 × 10
^{It is 12} to 1 × 10 ¹⁸ cm ⁻² . The impurity concentration A obtained from the mass spectrometer and the impurity injection amount B input from the injection controller are input to the calculator 20, and the injection amount C with the shortage corrected as given by the following equation is given.

[0026]

(Equation 1)

The beam current value obtained from the multipoint beam ammeter 17 is measured by the multipoint beam ammeter 17 and then mapped to a two-dimensional profile by the counting circuit 21 to obtain an in-plane beam current average value D. The final total injection amount G obtained by multiplying the injection amount C by the ratio F between the current value E obtained by the beam ammeter 13 and the beam current average value D is calculated by the computer 22 using the following equation, and integrated. The final total injection amount G is input to the ammeter 14.

[0028]

(Equation 2)

Here, the sample stage 11 is provided for, for example, setting a glass substrate 12 at the time of ion beam irradiation. It is desirable that the beam ammeter 13, the mass analyzer 16, and the multipoint beam ammeter 17 do not interfere with each other in the beam traveling direction. However, even if the multipoint beam ammeter interferes depending on the number and position of the arranged multipoint beam ammeters and the implementation status such as the ion beam intensity, the measurement is performed with a time difference of about 1 to 2 minutes. It is desirable to avoid interference.

FIG. 2 is a schematic plan view showing the structure of the manufacturing apparatus when the sample is doped. 2, the same reference numerals are used for the same parts as those shown in FIG. When impurities are injected up to the final total injection amount (total dose amount) set in the integrating ammeter 14, the switch 1
5 closes.

In the present embodiment, PH ₃ has been described as an example of the impurity ion generating gas, but PF ₅ , B ₂ H ₆ , BF ₃
Or the like may be used.

The mass spectrometry and the measurement and correction of the beam distribution can be measured at any time, and the time of the measurement and correction can be selected according to the use condition of the apparatus. For example, it is preferable to carry out the measurement in accordance with a certain work standard, such as measuring each processing lot or once a day.

Next, an active matrix type liquid crystal display device formed using the manufacturing apparatus according to the present invention in accordance with the manufacturing method according to the present invention will be described. As shown in FIG. 3, such an active matrix type liquid crystal display device includes a large glass substrate on which a gate electrode 1, a gate insulating film 2, a silicon semiconductor layer 3, an insulating thin film 4, and a source / drain electrode 7 are disposed. , And a liquid crystal display is performed by such a configuration. The size of the large glass substrate is, for example, 550 mm × 650.
mm.

The manufacturing apparatus and the manufacturing method according to the present invention include:
This is applied to formation of a portion of the silicon semiconductor layer 3 which is in contact with the source / drain electrode 7, that is, a source / drain region. That is, the source / drain region is formed in the silicon semiconductor layer 3 near the interface where the silicon semiconductor layer 3 and the source / drain electrode 7 are in contact. In the active matrix type liquid crystal display device formed in accordance with the manufacturing apparatus and the manufacturing method according to the present invention as described above, since the amount of impurity irradiation is accurately controlled, a liquid crystal display device having constant display characteristics can be always formed. It has the advantage that it can be done. Note that the display characteristics refer to, for example, a change in luminance of a liquid crystal display with respect to the magnitude of a voltage applied to a gate electrode or a source / drain electrode of a thin film transistor.

The above-mentioned multipoint beam ammeter, for example, when irradiating an ion beam on a region of a size of 550 mm × 650 mm, avoids a place for fixing a sample and measures 20 m.
Most preferably, they are arranged at intervals of m. When a plurality of multi-point ammeters are arranged in such a state, interference occurs in the traveling direction of the ion beam. Is preferably measured.

Next, it is preferable that the mass spectrometry and the measurement and correction of the beam distribution are performed periodically or immediately before the sample is irradiated with ions.

The active matrix type liquid crystal display device using amorphous silicon or polysilicon formed in such a most preferred embodiment has uniform display characteristics, and is stable and has good reproducibility in manufacturing. It has the advantage that it can be manufactured.

[0038]

As described above, according to the present invention, it is possible to accurately and promptly control the dose of impurity in response to a change in the state of the manufacturing apparatus or a change in the impurity concentration at the time of gas switching. it can. In addition, the thin film transistor manufactured using such a manufacturing apparatus can reduce variation in characteristics between lots or manufacturing dates.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a configuration of a manufacturing apparatus used for an ion doping method according to an embodiment of the present invention.

FIG. 2 is a schematic plan view showing a configuration of a manufacturing apparatus used for an ion doping method according to an embodiment of the present invention.

FIG. 3 is a cross-sectional process explanatory view showing a manufacturing process of a conventional thin film transistor.

FIG. 4 is a schematic plan view showing the configuration of a manufacturing apparatus used for a conventional ion doping method.

FIG. 5 is a schematic plan view showing the configuration of a manufacturing apparatus used for an ion doping method when measuring impurity ions.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gate electrode 2 Gate insulating film 3 Silicon semiconductor layer 4 Insulating thin film 5 Phosphorus ion 6 Injection layer 7 Source / drain electrode 8 Impurity ion generation gas 9 Ion source 10 Electrode 11 Sample stand 12 Glass substrate 13 Beam ammeter 14 Integrating ammeter 15 Ion source Power switch 16 Mass spectrometer 17 Multi-point beam ammeter 18, 21 Counting circuit 19 Injection controller 20, 22 Computer

Claims (8)

[Claims] When a thin film transistor including a pixel and a source / drain contact region is formed on a large glass substrate, at least one of a plurality of thin film layers constituting the thin film transistor is extracted from an ion source. A method for manufacturing a thin film transistor of an active matrix liquid crystal display device in which an impurity is injected by irradiating a beam, wherein a beam current is controlled based on previously measured impurity concentration data and previously measured beam distribution data. Controlling the total amount of beam irradiation to irradiate the sample in the processing chamber with the ion beam without performing mass separation. 2. The method according to claim 1, wherein a total beam irradiation amount is controlled based on a product obtained by multiplying a proportional constant obtained by comparing the impurity concentration data with the beam distribution data by a desired impurity irradiation amount. . 3. The method according to claim 1, wherein a total beam irradiation amount is controlled based on a quotient obtained by dividing a proportional constant obtained by comparing the impurity concentration data with the beam distribution data by a desired impurity irradiation amount. . 4. The method according to claim 1, wherein a total beam irradiation amount is controlled in accordance with an impurity implantation amount counted based on a total of the beam currents obtained as a result of integrating the beam currents. 5. An ion beam irradiator used for manufacturing a thin film transistor of an active matrix liquid crystal display device, wherein the ion beam irradiator includes a beam ammeter for measuring an ion beam current, and a mass spectrometer for measuring an impurity concentration. A multipoint beam ammeter for measuring the distribution of the ion beam at a plurality of measurement points, and control means for controlling a total beam irradiation amount based on the impurity concentration and the distribution data of the ion beam. Beam irradiation equipment. 6. The control means for controlling the total beam irradiation amount further comprises means for comparing impurity concentration data obtained from the mass analyzer with beam distribution data obtained from the multipoint beam ammeter. The ion beam irradiation apparatus according to claim 5, wherein 7. An ion beam irradiation apparatus according to claim 5, wherein said control means is an integrating ammeter. 8. An active matrix liquid crystal display device in which a thin film transistor including a pixel and a source / drain contact region is formed over a large glass substrate, wherein mass separation is performed on an ion beam extracted from an ion source. Without controlling the beam current based on the impurity concentration data measured in advance by the mass analyzer and the beam analysis data measured in advance by the multipoint beam ammeter, the total beam irradiation amount is controlled and the ion beam is controlled. And the source / drain contact region is formed.