JP3476582B2 - Anodizing apparatus and anodizing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anodizing device and an anodizing method for fixing an electrochemical reaction in a solution to a substrate to be subjected to the electrochemical reaction.

The present invention relates to an anodizing device and an anodizing device which, when anodizing a substrate or a metal on the substrate, provide electrical conduction between the metal and a conductor wire for supplying an electric current.
Regarding the method of conversion .

[0003]

2. Description of the Related Art FIG. 1 shows an outline of a conventional apparatus for anodizing a metal on a substrate. In FIG. 1, 10
1 is a water tank, 102 is a chemical conversion solution (electrolyte for anodizing), 103 is an anode side substrate (substrate), 104 is a metal to be anodized, 105 is an anodic oxide of metal 104,
106 is a cathode side electrode, 107 is a connector for energizing the metal 104 while holding the anode side substrate 103, 108 is a connector connected to the cathode electrode, 109
Indicates a DC power supply. Conventionally, using the device shown in FIG.
A DC voltage was applied to the electrode 106 and the metal 104 from a DC power supply 109 to form the anodic oxide 105.

[0004]

2. Description of the Related Art Conventionally, for example, metal 1
Aluminum is used as 04, and if the connector 107 on the anode side gets wet with the chemical conversion liquid while anodizing is performed on the aluminum so as to provide a barrier type anodic oxide film, the barrier type is formed. Due to the high insulation of the anodic oxide film of the
An electric current has flowed between and. For this reason, no current flows through aluminum, and the growth of the anodic oxide film does not proceed.

In order to prevent such a situation, conventionally, the connector 107 has been provided at a distance from the liquid surface of the chemical conversion liquid 102. Therefore, after the anodizing step is completed, it is usual that large non-anodized portions remain as shown in FIG. 4 (A).

Further, in order to stabilize the liquid surface of the chemical conversion liquid so that the connector is not covered with the solution, the chemical conversion solution was not stirred. Therefore, in order to make the liquid uniform, sufficient stirring is performed in the stage before the anodizing step, but the stirring is not performed in the stage of performing the chemical conversion. This is because the liquid surface slightly vibrates when stirred. Therefore, especially when a non-aqueous solvent type chemical conversion solution such as ethylene glycol is used, liquid separation has been a problem.

[0007]

An object of the present invention is to provide an anodizing device and an anodizing device which can stably supply a current from a power source to a metal which is anodized even when a chemical conversion solution comes into contact therewith.
It provides a method .

[0008]

In order to solve the above-mentioned problems, the present invention is for fixing a terminal to which a conductor covered with an insulator is electrically connected and a tip of the terminal to a conductive plane. And a means for confining at least the terminal and the conductive plane with which the tip of the terminal contacts in a closed space.

Further, according to the present invention, a terminal to which a conductive wire coated with an insulator is electrically connected, a fixing means for fixing the tip of the terminal to a conductive plane, and at least the terminal and the terminal. An anodizing device comprising: a connector configured to confine the electrically conductive plane with which the tip comes into contact in a closed space.

Further, according to the present invention, a terminal to which a conductive wire covered with an insulator is electrically connected, a fixing means for fixing the tip of the terminal to a conductive plane, and at least the terminal and the terminal. A connector having a means for confining the conductive plane with which the tip is in contact in a closed space, a tip of the terminal on the surface of a metal film formed on a substrate or an insulating film or a semiconductor on the substrate. After contacting and fixing to the substrate, the metal film is anodized, which is an anodizing method.

The present invention also provides a terminal to which a conductor covered with an insulator is electrically connected, a fixing means for fixing the tip of the terminal to a conductive plane, and at least the terminal and the terminal. Each of a plurality of connectors electrically connected to a power source independently of each other having a means for confining the electrically conductive plane with which the tip contacts and a closed space;
Formed on the substrate or on the insulating film or semiconductor on the substrate,
Corresponding to each of the plurality of metal films insulated from each other, the tip of the terminal is brought into contact with the surface of the metal film and fixed to the substrate, and then the metal film is anodized. This is a characteristic anodic oxidation method.

[0012]

With the connector of the present invention, it is possible to prevent a current from flowing from the connector into the solution due to the chemical conversion liquid during the electrochemical reaction using the solution, particularly the anodic oxidation of the metal on the substrate (base). A stable current can be supplied to the metal to be anodized.

That is, with the connector of the present invention, a connector having a conductive plane such as a metal film and a terminal which is in contact with the conductive plane and connected to a conducting wire for supplying an electric current are confined in a closed space. As a result, a solution such as a chemical conversion liquid is isolated from the terminal, and the terminals do not touch each other. Therefore, it is possible to prevent current from flowing from the connector to the solution. In addition, the conductive wire that is electrically connected to the terminal and that supplies the electric power from the power source is covered with an insulating film at least in a region that is in contact with or may contact the chemical conversion liquid, and a current flows through the solution from the conductive wire. Nothing.

FIG. 4 shows an anodized portion formed by a conventional anodizing method when a metal is provided on the entire surface of the substrate.
The non-anodized part and the anodic-oxidized part and non-anodized part formed by the anodic-oxidation method using the connector of this invention are shown. FIG. 4A shows a conventional anodic oxidation method, and FIG. 4B shows an anodic oxidation method using the connector of the present invention.

When the connector of the present invention is used, the entire substrate can be placed in the chemical conversion solution, so that FIG.
Since it is possible to make only the connector connecting portion not anodized, which is indicated by 403, the area of the non-anodized portion can be made extremely smaller than that of the conventional 401. That is, using the connector of the present invention, if the substrates have the same area, the area of the anodized portion 404 is as shown in FIG.
It can be made very large as compared with 402 in (B).

Therefore, for example, if an integrated circuit using an electrode having an anodized portion is manufactured in a substrate having a fixed area, the effective area becomes much larger than the conventional one, and the manufacturing cost is reduced. Can cause a decline.

Further, in an active matrix type liquid crystal electro-optical device or the like, metal wiring used for a gate electrode of a thin film transistor in order to form a thin film transistor having different characteristics such as a pixel thin film transistor on the same substrate and a peripheral drive circuit thin film transistor. The structure in which the anodic oxide film of is different is used.

In such a case, a plurality of feeding points (connecting regions with the connector) are provided in one substrate, and anodization is performed by varying the voltage, current and time for anodization. Since the connector of the present invention requires a small contact area for power feeding, the connector periphery can be designed to be extremely compact, and there is no problem even if the number of power feeding points is large.

As the packing means, various materials such as plastics, vinyl, ceramics, etc. can be used in addition to rubber materials such as O-rings. Examples will be shown below.

[0020]

【Example】

[Embodiment 1] In this embodiment, an embodiment concerning anodic oxidation of aluminum wiring patterned on an insulating substrate will be described. As the metal material to be anodized, not only aluminum but also titanium, tantalum, silicon, etc. can be used.

Description will be made with reference to FIG. FIG. 2 shows an outline of an anodizing apparatus for performing anodization using the connector of the present invention. First, an aluminum film, which is a material for forming wiring, was formed on an appropriate substrate 103 (generally an insulating film such as glass or an insulating material) to a thickness of 6000Å by a sputtering method. The thickness of this aluminum is not particularly limited as long as it is formed to the required thickness.
Further, Sc (scandium) is contained in aluminum in an amount of 0.
The one to which 2 wt% was added was used. This is to prevent aluminum hillocks from occurring in the subsequent anodizing process. Further, an additive (for example, Y) other than Sc may be used to prevent abnormal growth of aluminum at high temperatures.

Aluminum was patterned by a usual photolithography process. For the etching, dry etching or wet etching is performed. In dry etching, the etching cross section becomes close to a right angle. Further, in wet etching, the angle formed by the cross-section with the substrate is smaller than 90 ° and is approximately 40 to 60 °. In the case of a wiring electrode, if the etching cross section is close to 90 °, an interlayer insulating film or 2
There is a problem that the step coverage of the layer wiring deteriorates and the probability of causing a disconnection or a short circuit between the upper and lower wirings increases. Therefore, wet etching is adopted in this embodiment. A solution of phosphoric acid, acetic acid, and nitric acid is mixed with 35-4.
The one heated to 5 ° C. was used.

As a result, a 10 mm square rectangular electrode portion was formed on the substrate as a region for connecting the connector of the present invention, and the other portion was formed by processing aluminum into a stripe shape having a width of 60 μm to form a wiring. These wirings are electrically connected to the rectangular electrode portion to which the connector is connected in order to anodize all of them.

The anode of the power source 208 is connected to the aluminum pattern 104 which is the wiring on the substrate by the connector of the present invention. The structure of the connector of the present invention will be described. Wiring 207 on the anode side from the power supply 208 for oxidation
Is electrically connected to the contact terminal 209 from the middle. The contact terminal 209 comes into contact with the aluminum pattern 104 on the substrate 103 to make a contact.

The wiring 207 is covered with an insulating material 206 such as Teflon, silicon rubber or polyethylene, and in the connector, O-rings 201, 20 as packing means are provided.
It is sealed by 5 to prevent the invasion of the solution. Further, the contact terminal 209 has the aluminum pattern 104.
In order to make a stable contact with, the contracting material 203 has a structure in which it is pushed toward the processed substrate with a constant force. Shrink material 203
As the material of spring, natural rubber, silicone rubber,
A foaming agent or the like is used. Anything that has contraction and elasticity like this is good.

The substrate 103 is sandwiched between the opposing wall 212 of the connector and the contact O-ring 201. The contact O-ring is designed so that the chemical solution does not enter inside the contact O-ring.
In the above-mentioned rectangular electrode portion, the aluminum pattern 1
04 and the O-ring are firmly attached to each other to form a closed space 210
Are adjusted to form. The opposing wall 212 of the connector, which is the fixing means, is structured to be pushed toward the contact O-ring side by a screw, a spring, or the like as necessary.
The tip of the contact terminal 209 is attached to the aluminum pattern 104.
Fixed to. In this way, the contact terminals 209 can form a contact with the aluminum pattern 104 having sufficient electrical conduction in the closed space separated from the solution.

The substrate to which the connector is connected is the chemical conversion liquid 1
It will be stored in 02. Since the substrate and the connector are electrically insulated from the solution, they can be completely inserted below the liquid surface 211. If it is not necessary to completely insert it in this way, it is sufficient to insert up to the desired part.

In the drawing of FIG. 2, the connector portion is drawn large with respect to the substrate, but the diameter of the contact O-ring is 5
It is sufficient if it is 10 mm or less, and only that portion becomes a portion that is not anodized. This is a major difference from conventional anodizing connectors.

An electrode on the cathode side is also placed in the chemical conversion liquid. The electrode material was used platinum or stainless plate. Although the connector of the present invention is not shown on the cathode side, this connector may be used.

A charge is supplied from a power source 208 to both electrode pairs,
The aluminum pattern 104 was anodized. FIG. 3 shows changes in current and voltage between the anode and the cathode during the anodizing process. The aluminum on the anode side is supplied with a positive charge and is oxidized, and when the power source on which the insulating film is formed is kept in the constant voltage mode in which the current 302 is constant, the voltage 301 between the anode and the cathode increases for a while. When the ultimate voltage reaches 120 V, the power mode is switched to the constant voltage mode.
Minute anodic oxidation was performed. It can be seen that in this mode, the current drops sharply and the film resistance continues to rise. The thickness of the anodic oxide film formed by this process is 150
It was 0Å. The anodic oxide film formed here was a barrier type anodic oxide having a dense composition.

Since the aluminum pattern has a tapered cross section, it is also tapered after the anodic oxide film is formed. After baking this aluminum pattern at 150 to 350 ° C., a withstand voltage is 100 to 110 V when a voltage is applied to the anodic oxide film to cause permanent breakdown.
Therefore, the aluminum was covered with an extremely good insulating film.

[Embodiment 2] This embodiment shows an example in which different anodic oxidation widths are formed in the same step. In this embodiment, an insulating gate type thin film transistor (TFT) using a crystalline semiconductor having different characteristics is formed on the same substrate.

5 and 6 show steps of manufacturing different kinds of TFTs in the second embodiment. 6A, 6B,
5C shows a plan view substantially corresponding to FIGS. 5A, 5C, and 5E, respectively. Further, FIG. 5 is a cross section of a portion indicated by a chain line in FIG. First, on a substrate (Corning 7059, 300 mm × 300 mm or 100 mm × 100 mm) 501, a thickness of 1000
A silicon oxide film 502 of about 3000 Å was deposited by the sputtering method. This may be formed by the plasma CVD method.

After that, an amorphous silicon film of 300 to 150 is formed by a plasma CVD method or an LPCVD method.
0 Å, preferably 500-1000 Å is deposited and patterned to form island silicon regions 503 and 504.
Was formed. Then, silicon oxide having a thickness of 200 to 1500 Å, preferably 500 to 1000 Å was formed by a sputtering method or a plasma CVD method. Since this silicon oxide film also functions as a gate insulating film, great care must be taken in its fabrication. For example, when the plasma CVD method is used, TEOS is used as a raw material, and the substrate temperature is 150 to 400 ° C., preferably 200 to 250 ° C. together with oxygen.
Then, RF discharge was performed to decompose and deposit the raw material gas. TE
The pressure ratio of OS and oxygen is 1: 1 to 1: 3, the pressure is 0.05 to 0.5 torr, and the RF power is 100 to 25.
It was set to 0W. Alternatively, by using TEOS as a raw material together with ozone gas by a low pressure CVD method or a normal pressure CVD method,
Substrate temperature is 150 to 400 ° C., preferably 200 to 25
You may form as 0 degreeC.

Then, a KrF excimer laser (wavelength 248 nm, pulse width 20 nsec) was irradiated to crystallize only the silicon region 503. The energy density of the laser is 200 to 400 mJ / cm ² , preferably 2
It was set to 50 to 300 mJ / cm ^2, and the substrate was heated to 300 to 500 ° C. during laser irradiation. XeCl excimer laser (wavelength 308n)
m) and others may be used. The silicon region 504 remained amorphous.

Thereafter, an aluminum film having a thickness of 2000 Å to 5 μm, for example, 6000 Å is formed by an electron beam evaporation method, and is patterned to form a gate electrode 5
06, 507, 509 and the wiring 508 were formed. Scandium (Sc) is added to aluminum in an amount of 0.05 to 0.
When 3 wt% was doped, generation of hillocks due to heating was suppressed. This state is shown in FIG.
It shows in (A). As is clear from FIG. 5A, the gate electrode 509 and the wiring 508 are electrically connected, and the gate electrodes 506 and 507, the gate electrode 509, and the wiring 508 are electrically independent. . Below, the former is A
The series and the latter are called the B series. Next, using the connector shown in Example 1, the substrate is immersed in a solution of tartaric acid in ethylene glycol having a pH of 7 and 1-3%, and anodization is performed using platinum as a cathode and this aluminum gate electrode as an anode. It was The anodic oxide obtained by using such a neutral solution is called a barrier type anodic oxide and is dense and has a high withstand voltage.

The connectors shown in FIG. 2 are connected one by one to the connection areas with the connectors serving as the feeding points of the A series and the B series, which are provided in the peripheral portion of the board, and the conductors of the respective connectors are mutually connected. It is connected to a power source that can be controlled independently. The substrate 501 to which these two connectors were connected was placed in the chemical conversion liquid so that the connectors were also below the liquid surface.

In the anodic oxidation, first, a constant current was continuously applied to both the A series and the B series, the voltage was raised to the _first voltage V ₁ , and the state was maintained for 1 hour. After that, while maintaining the voltage V _{1 in the} A series, a constant current was continuously applied to the B series, and the voltage was increased to the second voltage V ₂ . Since the two-step anodic oxidation was performed in this way, the A series and B
The thickness of the anodic oxide formed on the side surface and the upper surface of the gate electrode is different from that of the series, and the latter is thicker. V ₁
Is preferably 50 to 150 V, and here 10
It was set to 0V. V ₂ is preferably 100 to 250V, and here, 200V. In the present example, in the constant current state, the rate of increase in voltage was 2 to 5 V / min. Naturally, V ₁ <V ₂ . As a result, A
The thickness of the series gate electrodes 506 and 507 is about 120.
0 Å anodic oxides 510 and 511 are formed on the gate electrode 509 and the wiring 508.
12, 513 were formed respectively. (Fig. 5 (B))

After that, impurity ions (phosphorus, boron) are implanted into the island-shaped silicon film of each TFT by an ion doping method (also referred to as a plasma doping method) by using the known CMOS technology and self-aligned impurity implantation technology. did.
Phosphine (PH ₃ ) and diborane (B ₂ H ₆ ) were used as the doping gas. Dose amount is 2-8x
It was set to 10 ¹⁵ cm ^-2 . As a result, N-type impurity (phosphorus) regions 514 and 516 and P-type impurity (boron) regions 515 are formed.
Was formed. It is the NTFT 526, 52 in the drawing.
8 to form the PTFT 527.

Furthermore, a KrF excimer laser (wavelength 248 nm, pulse width 20 nsec) was irradiated to improve the crystallinity of the portion where the crystallinity was deteriorated by the introduction of the impurity region. Laser energy density is 150 ~
400 mJ / cm ² , preferably 200-250 mJ /
It was cm ² . Thus, the N-type impurity regions 514, 5
16 and P-type impurity region 515 were activated. The sheet resistance in these regions was 200 to 800 Ω / □. This step may be performed by RTA (rapid thermal annealing). (Fig. 5 (C), Fig. 6 (B))

Through the above steps, the width of the offset region (high resistance region) of each TFT was determined. That is, in the two TFTs on the left side of FIG.
Since the thicknesses of 0 and 511 are about 1200Å, the offset widths x ₁ and x ₃ are about 1000Å considering the wraparound at the time of ion doping, and in the TFT on the right side, the thickness of the anodic oxide 513 is about 2400Å. So offset width x ₂
Was about 2000Å. (See FIG. 5D) Offset width x of TFTs 526 and 527 for high frequency operation
It is necessary that ₁ and x ₃ are smaller than the offset width x _{2 of the} NTFT 528 that requires a low off current. However, since the NTFT is apt to be frequently deteriorated by hot carriers due to the reverse bias of the drain, it is preferable to make the offset width larger than that of the PTFT. That is,
x ₃ > x ₁ . Further, since the off-state current is small and the NTFT 528 to which a high drain current is applied has a large offset width, x ₂ > x ₃ .

After that, the gate electrode and wiring (see FIG.
530) of (C) was divided into pieces to obtain the length required for the circuit. Then, TEOS is formed on the entire surface as an interlayer insulator 517.
As a raw material, a silicon oxide film having a thickness of 3000 to 10000 Å, for example, 6000 Å was formed by a plasma CVD method using oxygen and oxygen, or a low pressure CVD method using ozone or a normal pressure CVD method. At this time, if fluorine is reacted with dicarbon hexafluoride (C ₂ F ₆ ) and added into silicon oxide, the step coverage can be improved. Substrate temperature is 1
It was set to 50 to 400 ° C, preferably 200 to 300 ° C. Furthermore, an ITO film is deposited by the sputtering method,
This was patterned to form a pixel electrode 518. Then, the interlayer insulator 517 and the anodic oxide 512 of the wiring 508 were etched to form a contact hole 519. (Fig. 1 (D))

After that, the interlayer insulating film and the gate insulating film 505 are formed.
Was etched to form contact holes in the source / drain of the TFT. Although not shown in FIG. 5, during the formation of this contact hole, the anodic oxide 51 was simultaneously formed.
Gate electrodes 506 and 5 are also etched by etching 0 and 511.
A contact hole is also formed in 07. (Fig. 6
(See (C)) Then, the wiring 52 of the multilayer film of titanium nitride and aluminum
0-525 was formed. The wiring 524 was connected to the pixel electrode 518. Further, the wiring 525 is connected to the gate electrodes 506 and 507 through the contact holes previously formed. Finally, in hydrogen at 200-300 ° C.
Annealed for 2 hours to complete hydrogenation of silicon. In this way, the integrated circuit is completed. (FIG. 5 (E), FIG. 6 (C))

In this example, the step of etching the thick anodic oxide 513 to form a contact hole and the step of forming other contact holes were separately performed. Of course, this may be done at the same time, but in the present embodiment, the mass production was sacrificed, and the purpose was to do so. This is because the barrier type anodic oxide obtained in this example has an extremely small etching rate as compared with silicon oxide or the like, and if both are simultaneously etched, the barrier layer is covered with a silicon oxide film that is easily etched. This is because the exposed contact holes to the source and drain are largely etched and holes are formed in the source and drain.

In this way, different kinds of TFTs were formed on the same substrate. That is, 2 on the left side of FIGS.
The two TFTs 526 and 527 have an active layer of crystalline silicon and a high resistance region (offset region) having a small width and are suitable for high speed operation. The TFT 529 on the right side has an active layer of amorphous silicon and has a high resistance region (offset region). It has a wide width and is characterized by low leakage current. T
Active layer of FT528 same effect can be obtained even at a low crystalline silicon of the degree of crystallization than TFT527,528. Needless to say, when a monolithic active matrix is manufactured using the same process, the former may be used for a driver circuit and the latter may be used for an active matrix circuit.

Degradation due to hot carriers is often seen in NTFT, but driver TFT with a large channel width
Not much is observed at (this offset width is x ₄ ). In addition, a decoder circuit that requires high-frequency operation, particularly shift register, CPU, memory, and other correction circuit NTFT (offset width is x ₃ )
Requires a small channel width and a small channel length. Therefore, the TF in the active matrix circuit is
T528 is small (the offset width is x ₂₎ deterioration due drain voltage is lower than. Therefore, x ₄ <
It is required that x ₃ <x ₂ . And PTFT
Since the offset width x ₁ of ₁ is hardly deteriorated in the driver TFT or the auxiliary circuit other than the driver TFT, x ₁ ≦ x ₄ is allowed.

In this embodiment, the series of different anodic oxidation widths is two systems A and B, but the number of connectors or the number of terminals in the connector may be increased to provide three or more systems.

[Embodiment 3] This embodiment shows an example in which the present invention is applied to an inverted stagger type insulating gate type thin film transistor (TFT). Further, in this embodiment, an example in which an aluminum wiring serving as a gate electrode on a substrate is anodized to form a matrix structure of 640 × 480 to form an active matrix circuit in which an insulating gate type thin film transistor is provided in each pixel is formed. Show.

FIG. 7 shows a manufacturing process of the insulating gate type thin film transistor on the glass substrate manufactured in this embodiment. Although only one thin film transistor is shown in the figure, it is formed in a matrix on the substrate to be paired with the pixel electrode to be connected. First, the substrate (Corning 705
(9, 200 mm × 200 mm) 701 and underlying film 702
As a result, a silicon nitride film having a thickness of 1000 to 3000 Å, for example 2000 Å, was formed by the sputtering method. Instead of the silicon nitride film, a silicon oxide film may be provided with a similar thickness. In this case, a sputtering method in an oxygen atmosphere is used as a method for forming the silicon oxide film. However, in order to further improve mass productivity, a film obtained by decomposing / depositing TEOS by the plasma CVD method may be used.

Next, the thickness is 1000Å to 2 μm, for example,
A 2800Å aluminum film (containing 1 wt% Si or 0.1 to 0.3% wt Sc) was formed by an electron beam evaporation method or a sputtering method. The formed aluminum film is patterned by a wet etching process using a mixed solution of phosphoric acid, nitric acid, and acetic acid so as to have a tapered cross section, and the gate electrode portion 70 is formed.
Formed 3. (Figure 7 (A))

FIG. 8 shows an aluminum pattern 801 on the substrate 701 formed here. In FIG.
A connection region 802 with which the connector contacts is formed near the end of the substrate 701 together with the patterning of the gate electrode portion 703. The connection region 802 is electrically connected to all the gate electrode portions 703 on the substrate 701.

Next, the connector shown in Example 1 was placed on the gate electrode portion 703 so that the O-ring was in contact with the connection region 802, and anodization was performed.

As the anodizing solution 408, an anodizing solution having a pH of 7 obtained by neutralizing an ethylene glycol solution in which 3% tartaric acid was dissolved with ammonia was used. A current was passed between the aluminum wiring pattern 801 on the substrate 701 and the cathode electrode 402 to start anodization. Constant current value,
Here, the current density is 0.5 mA / cm ² and the voltage is 120
Current was applied until V was reached. After reaching 120V, it was maintained at 120V for 1 to 60 minutes, here 10 minutes.

In this way, the gate electrode portion 703 is
Barrier type anodized aluminum 705 was formed on the upper surface and the side surface of the gate electrode 704. The thickness of the anodized aluminum 705 was about 1600Å as the voltage was raised to 120V.

Through the above steps, the gate electrode 704 made of aluminum and the gate insulating film 705 made of anodized aluminum could be formed. (Fig. 7
(B))

Then, in the atmosphere, 200 to 300 ° C., eg, 2
When heated at 00 ° C. for several to several tens of minutes, the leak current of anodized aluminum was reduced by one digit or more, which was preferable.

Next, silane and ammonia were added in a ratio of 1: 3 to 1: 8.
Here, a silicon nitride film is used as the second-layer gate insulating film 706 by a plasma CVD method with a ratio of 1: 5.
000-3000Å, for example 2000Å. Instead of the silicon nitride film, a silicon oxide film may be provided with a similar thickness. As a method for forming the silicon oxide film, a sputtering method in an oxygen atmosphere or a plasma CVD method is used. When the plasma CVD method is used, TEOS is used as a raw material, and the substrate temperature is 150 to 400 ° C., preferably 20 with oxygen.
RF discharge was performed at 0 to 250 ° C. to decompose and deposit the source gas. The pressure ratio of TEOS and oxygen is 1: 1 to 1: 1.
0, the pressure was 0.05 to 0.5 torr, and the RF power was 100 to 250W. Alternatively, TEOS may be formed with ozone gas as a raw material by a low pressure CVD method or a normal pressure CVD method at a substrate temperature of 150 to 400 ° C., preferably 200 to 250 ° C. The gate insulating film 706 need not be provided, but if it is provided,
It is possible to reduce the short circuit between the electrodes and improve the mutual conductance of the thin film transistor.

Two I-type amorphous silicon films 707 forming a channel formation region are formed on the gate insulating film 706.
It was formed in the range of 00 to 2000Å, for example 1000Å. Further thereon, a silicon nitride film of 500 to 3000 Å, here 1000 Å, was formed. Pure with respect to the formed silicon nitride film
The protective film 708 was formed by etching with hydrofluoric acid diluted to 1/10 to 1/50 with water . Further, an n ⁺ amorphous silicon film 709 containing phosphorus was formed thereon by plasma CVD to a thickness of 200 to 1000 Å, here 300 Å. (Fig. 7 (C))

Next, the I-type amorphous silicon film 70 is formed.
7 and n ⁺ amorphous silicon film 709 were dry-etched and patterned. On the other hand, an ITO (indium oxide / tin) thin film to be the pixel electrode is also formed
Patterned (not shown). Then, an aluminum film is formed on the substrate by electron beam evaporation method or sputtering method to 1000
˜2 μm Here, it is formed to a thickness of 3000 Å. Then, this aluminum film and the n ⁺ amorphous silicon film thereunder are etched and patterned by dry etching to form a source electrode 710 and a drain electrode 711, and the n ⁺ amorphous silicon film thereunder is formed into a source region and a drain region. Then, the thin film transistor was completed. (Figure 7 (D))

The active matrix circuit thus formed was used in a liquid crystal electro-optical device, and good characteristics could be obtained.

【effect】

By using the connector of the present invention,
Since the insulating property can be secured in the chemical conversion liquid, a stable current can be supplied to the metal to be anodized regardless of whether or not the connector touches the solution. Therefore,
It is not necessary to control the chemical conversion liquid surface during the anodizing process, which is very troublesome in conventional anodizing.

Furthermore, since the stability of the liquid surface as in the conventional case is not so serious, the chemical conversion liquid can be sufficiently stirred. Therefore, a great effect that the stability of oxidation is improved and the film quality can be made uniform is obtained.

[Brief description of drawings]

FIG. 1 shows an outline of a conventional device

FIG. 2 shows an outline of an apparatus for performing anodization using the connector of the present invention.

FIG. 3 shows changes in current and voltage between an anode and a cathode during the anodizing process.

FIG. 4 shows an anodized portion / non-anodized portion formed by a conventional anodizing method and an anodized portion / non-anodized portion formed by an anodizing method using the connector of the present invention.

5A to 5D are cross-sectional views in a manufacturing process of a TFT circuit according to a second embodiment.

6A to 6D are top views in the manufacturing process of the TFT circuit according to the second embodiment.

FIG. 7 shows a process of manufacturing an insulating gate type thin film transistor on a glass substrate manufactured in Example 3.

FIG. 8 shows a pattern of aluminum on a substrate.

[Explanation of symbols]

101 Water Tank 102 Chemical Solution 103 Anode Side Base 104 Anodized Metal (Aluminum Pattern) 105 Anodic Oxide 106 Cathode Side Electrode 107 Connector 108 Connector 109 DC Power Supply 201 O Ring 202 O Ring 203 Shrink Material 205 O Ring 206 Insulation Object 207 Wiring 208 Power supply 209 Contact pin 210 Closed space 211 Liquid level 212 Opposing walls 401, 403 Non-anodized regions 402, 404 Anodized region 501 Substrate 502 Base insulating films 503, 504 Island-like semiconductor region (silicon) 505 Gate insulation Film (silicon oxide) 506 to 509 Gate electrode / wiring (aluminum) 510 to 513 Anodic oxide (aluminum oxide) 514, 516 N-type impurity region 515 P-type impurity region 517 Interlayer insulator (silicon oxide) 518 Pixel electrode (I O) 519 contact holes 520 to 524 metal wires (titanium nitride / aluminum) 701 substrate 702 underlying film 703 gate electrode 704 gate electrode 705 anodized aluminum 706 silicon nitride film 707 I-type amorphous silicon film 708 protective film 709 n ⁺ amorphous silicon 710 source electrode 711 drain electrode 801 aluminum pattern 802 on substrate 701 contact area

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshimitsu Onuma 398 Hase, Atsugi City, Kanagawa Pref., Semiconductor Energy Laboratory Co., Ltd. (56) References 59-9079 (JP, U) (58) Fields investigated (58) Int.Cl. ⁷ , DB name) H01R 9/16 101 C25D 21/00 C25D 17/08

Claims (9)

(57) [Claims] [Claim 1] In Chemical solution a positive electrode oxidizer that form a positive electrode oxide has a connector and power, said connector for supplying power from said power supply
The terminal connected to the conductor wire and the tip of the terminal is anodized
And means for fixing to contact the substrate to form the object, before
From the chemical conversion solution, the terminal and the tip of the terminal are
And means for isolating the portion in contact with the plate, the conductor is in contact with at least the conversion solution or contact
Where possible, cover it with an insulator.
Ri, by means of the fixed, pressing the tip of the terminal to the substrate <br/>, anodizing apparatus characterized by securing the substrate to the connector. In 2. A chemical solution to a positive pole oxidation apparatus that form a positive electrode oxide, a plurality of connectors and a power, the plurality of connectors from each of the one power
A terminal connected to a conductor for supplying electric power, means for fixing the tip of the terminal so as to contact the substrate forming the anodic oxide, and the terminal and the tip of the terminal from the chemical conversion solution. Means for isolating the portion in contact with the substrate
And the conductive wire contacts or contacts at least the chemical conversion solution.
Where possible, cover it with an insulator.
Ri, by means of the fixed, pressing the tip of the terminal to the substrate <br/>, anodizing apparatus characterized by securing the substrate to the plurality of connectors. 3. A positive electrode oxidizer that form a positive electrode oxide with chemical solution, a plurality of connectors and a plurality of power, the plurality of connectors, each power supply different from each other
A wire for supplying power from the power source, which is connected to
Shape and connected terminal, the tip of the terminal anodic oxide
And means for fixing to contact the substrate to be formed, the chemical conversion
From the solution, contact the terminal and the tip of the terminal with the substrate.
And means for isolating a portion touching the wire is in contact with at least the conversion solution or contact
Where possible, cover it with an insulator.
Ri, by means of the fixed, pressing the tip of the terminal to the substrate <br/>, anodizing apparatus characterized by securing the substrate to the plurality of connectors. 4. The means for isolating the formation solution of the substrate and the surface on which the terminal and the tip of the terminal come into contact with each other, from a rubber, a plastic, a vinyl and a ceramics according to any one of claims 1 to 3. An anodizing device, characterized in that it is made of any of the above materials. 5. The O-ring according to any one of claims 1 to 3 , wherein the means for separating the formation solution of the terminal and the formation surface of the substrate with which the tips of the terminals come into contact with each other is the O-ring. Anodizing device. 6. A any one of claims 1 to 5, an insulator covering the conductor, Teflon, anodization apparatus characterized by comprising either a material such as silicon rubber and polyethylene. 7. In any one of claims 1 to 6, means for securing the front end of the terminal to the formation surface, the feature spring, natural rubber, to become of any material of silicone rubber and a foaming agent Anodizing device. 8. Using the anodizing apparatus according to any one of claims 1 to 7, forming an anodic oxide on the surface of the metal film formed on an insulating film or a semiconductor film on the substrate or on a substrate An anodic oxidation method comprising: 9. An anodic oxide is formed on the surface of a metal film formed on a substrate or an insulating film or a semiconductor film on the substrate by using the anodizing apparatus according to any one of claims 1 to 8. a anodizing process, the metal film and the connector disposed conversion solution during anodic oxidation method characterized by forming an anodic oxide on the surface of the metal film.