JP3941356B2 - Manufacturing method of electro-optical device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing an electro-optical device or a semiconductor device, and more particularly, an electro-optical device having a reflective layer made of a silver thin film, an electrode or circuit wiring, or a semiconductor having an electrode or circuit wiring made of a silver thin film. The present invention relates to a device manufacturing method.
[0002]
[Prior art]
A liquid crystal display device is a non-light-emitting display device in which a liquid crystal substance is sandwiched between a pair of substrates arranged opposite to each other, and performs display by modulating light passing through the liquid crystal according to the alignment state of the liquid crystal. is there. As a display method of such a liquid crystal display device, a transmissive type and a reflective type or a transflective type are known.
Among these, the transflective liquid crystal display device 150 shown in FIGS. 16 and 17 is an active matrix TFD (Thin Film Diode) liquid crystal display device, and one substrate 141 and the other substrate 142 are predetermined. The liquid crystal 140 is sandwiched between the substrates 141 and 142 so as to face each other with a gap therebetween. Here, one substrate 142 is an element substrate, and a plurality of electrodes (for example, ITO (Indium Tin Oxide)) made of transparent electrodes such as ITO (Indium Tin Oxide) are formed on the lower surface (opposing surface) of a transparent substrate 143 made of glass or the like. Pixel electrode) 144 and a TFD 148 for controlling the pixel electrode 144 are provided. Each pixel electrode 144 is formed in a substantially rectangular shape, and a TFD 148 is disposed at one corner thereof, and this portion is a notch. The TFD 148 is connected to the scanning line 146, and controls the display operation by switching the liquid crystal to a display state, a non-display state, or an intermediate state based on a signal applied to the scanning signal and the data line (counter electrode) 166. Be able to.
[0003]
In the liquid crystal display device of FIG. 16, the other substrate 141 is a filter substrate, and a reflective layer 154 made of a metal film is formed on almost the entire surface of a transparent substrate 152 made of glass or the like. A strip-shaped electrode (counter electrode) 166 made of ITO and forming a data line is formed on the reflective layer 154 via color filters 160, 162, 164. Natural light 80 incident from above the substrate is reflected by the reflective layer 50 and enters the field of view. Further, a small rectangular window 154 a is formed in the reflective layer 154 in the vicinity of the center of each color filter layer 160, 162, 164, and the light source (backlight) 70 disposed on the outside of one substrate 141. Light is transmitted to the other substrate 142. In other words, the liquid crystal display device 150 performs reflection display by the reflection layer 154 at the peripheral portions of the color filter layers 160, 162, and 164, and performs transmission display by the window 154a at the central portion.
[0004]
Each of the color filter layers 160, 162, and 164 is provided in a matrix at a position facing the pixel electrode 144 of one substrate 142, and includes a blue color filter layer (illustrated “B”) 160 and a green color filter layer (illustrated “ G ”) 162 and a red color filter layer (“ R ”in the drawing) 164. Here, since each color filter layer constitutes the three primary colors (R, G, B) of light, it is preferable that R, G, B are alternately arranged in any direction. In the figure, R, G, and B are repeatedly arranged from left to right. In addition, the color filter layers 160, 162, and 164 are spaced apart and correspond to a non-image display region (region in which the pixel electrode 144 is not formed on the other substrate 142) between them. Thus, a light shielding layer 156 is formed. A protective layer (not shown) is formed on each color filter layer 160, 162, 164, and a counter electrode 166 is formed on the protective layer so as to intersect the extending direction of the scanning line 146. .
In the liquid crystal display device 150 illustrated in FIG. 16, an example in which the TFD is used to control the pixel electrode 144 is shown. However, an active matrix liquid crystal display device using a TFT (Thin Film Transistor) instead of the TFD may be used. Of course it is good.
[0005]
FIG. 17 shows a cross-sectional structure along the line AA ′ in FIG. 16 of the liquid crystal display device 150 described above. In FIG. 17, the peripheral edge of the window 154 a is located inside the peripheral edge 144 a of each pixel electrode 144. Further, the light shielding layer 156 is formed on the substrate 152 of one substrate 141, more specifically, on the reflective layer 154 formed on the substrate 152. The peripheral edge 156a of the light shielding layer 156 is located slightly outside the peripheral edge 144a of each pixel electrode 144, and there is no opposing pixel electrode between the peripheral edge 156a and the peripheral edge 144a. Is formed. A counter electrode 166 is formed on each of the color filter layers 160, 162, 164 and the light shielding layer 156 via a protective layer 168 made of, for example, an acrylic resin.
In the liquid crystal display device having such a structure, the metal film to be the reflective layer 154 is not particularly limited, but has high light reflectivity such as aluminum, aluminum alloys (aluminum-neodymium, aluminum-palladium-copper, etc.), silver, and the like. A thin film of metal such as nickel, titanium or chromium is used. The reflective layer 154 has a light reflectance of 85% or more, more preferably 90%, and aluminum or aluminum alloys with a light reflectance of 90% are often used in consideration of the price.
The scan line 146 and the signal line (not shown) are preferably made of a metal having a low electrical resistivity, and aluminum, chromium, nickel, tantalum, or the like is frequently used in consideration of the film forming method and the ease of patterning.
In various semiconductor devices, a metal having a low electrical resistivity must be used for the electrode portion and the wiring structure portion, and aluminum, chromium, nickel, tantalum, etc. It is used a lot.
[0006]
[Problems to be solved by the invention]
However, the light reflectivity of aluminum or aluminum alloy used as a metal thin film for reflectors is on the order of 90% at most, and the use of a metal thin film with higher light reflectivity for obtaining a clear display image is required.
In addition, to improve the performance of various semiconductor devices, metal with lower electrical resistivity in the electrode part and wiring structure part is used to improve the signal transmission speed in the wiring material and suppress the heat generation of the semiconductor device. However, it is necessary to reduce power consumption.
From this point of view, silver (Ag) may be mentioned when a metal having high light reflectance and low electrical resistivity is studied. Incidentally, the light reflectance of silver is 98%, which is much higher than the light reflectance of aluminum alloy. Moreover, the electrical resistivity (electric resistivity) of silver is 1.50 × 10 ^-6 Ω · cm, 32.1 x 10 of aluminum ^-6 Ω · cm, chrome 13 × 10 ^-6 Ω · cm, tantalum 12.4 × 10 ^-6 Ω · cm or nickel 6.58 × 10 ^-6 It has a much lower specific resistance than Ω · cm or the like. As a low-resistance conductive material, copper (electrical resistivity: 1.55 × 10 ^-6 However, if copper is used as the wiring material, it is necessary to take measures against oxidation. If this is neglected, it will be oxidized by oxygen and moisture in the air and will easily become copper oxide. As a result, the original low resistivity characteristic of copper is impaired. For this reason, the use of copper in semiconductor devices has not been put into practical use. Silver has a lower specific resistance than copper.
[0007]
If a silver thin film can be used in this way, further improvement in performance of liquid crystal display devices and various semiconductor devices can be expected. Conventionally, when forming a reflector or circuit wiring part of a liquid crystal display device using silver, or forming an electrode or circuit wiring part of a semiconductor device, a method of patterning by wet etching after forming a silver thin film is known. It was done. However, the method of patterning by wet etching has a problem in terms of patterning accuracy, and there is a limit when a finer and more accurate silver pattern is required. Dry etching is advantageous for patterning with higher accuracy. In view of the abatement equipment, dry etching is advantageous in terms of equipment. However, a dry etching method for a silver thin film has not yet been established.
From such a point of view, the present invention forms a silver pattern by dry etching a silver thin film with high accuracy and is used for a reflector or a circuit wiring part of a liquid crystal display device or an electrode part or a circuit wiring part of a semiconductor device. Is to provide a method.
[0008]
[Means for Solving the Problems]
The present invention has been made to solve the above-mentioned problems, and in one part, a liquid crystal is held between a pair of substrates, and electrodes are formed on opposite surfaces of each substrate, respectively. An electro-optical device manufacturing method in which a reflective layer made of a silver (Ag) thin film is formed between an electrode of at least one substrate and a substrate, and after the silver thin film is formed, the silver thin film is vaporized with an iodine (I) compound. This is a method of manufacturing an electro-optical device that uses a dry etching to form a silver reflective layer pattern of a predetermined shape.
In another aspect of the present invention, the liquid crystal is held between a pair of substrates, and at least one opposing surface of each substrate is composed of an electrode made of a silver (Ag) thin film or a silver (Ag) thin film, but a circuit wiring. A method of manufacturing a formed electro-optical device, wherein a silver electrode pattern or a silver circuit wiring pattern having a predetermined shape is formed by dry etching the silver thin film using an iodine (I) compound vapor after forming the silver thin film. An electro-optical device manufacturing method.
[0009]
Furthermore, another present invention is a method of manufacturing a semiconductor device having an electrode or circuit wiring made of a silver (Ag) thin film on a semiconductor substrate, and after the silver thin film is formed, the silver thin film is vaporized with an iodine (I) compound. It is a method for manufacturing a semiconductor device in which a silver electrode pattern or a silver circuit wiring pattern having a predetermined shape is formed by dry etching.
This method is a method in which a silver (Ag) thin film is captured by iodine (I) to form silver iodide (AgI), and silver iodide is diffused and etched by utilizing its high ion conductivity. According to this method, the silver thin film can be etched uniformly and efficiently, and even a fine silver pattern can be formed with high accuracy. Further, since no damage is given to the base layer during etching, and it is advantageous in terms of cost, it can be used as a metal reflection layer and circuit wiring of a liquid crystal display device, or as an electrode or circuit wiring of a semiconductor device.
In the method of manufacturing an electro-optical device or a semiconductor device according to the present invention, when the silver thin film is dry-etched using iodine compound vapor to form a predetermined shape silver pattern, the substrate is heated to a temperature of 147 ° C. or higher. It is characterized in that etching is carried out by changing the phase of silver iodide to α phase.
Silver iodide has three transformations: a γ phase that is stable from room temperature to 137 ° C, a β phase that has a wurtzite structure that is stable from 137 ° C to 147 ° C, and an α phase that is stable at temperatures from 147 ° C to the melting point. Phase transition to crystals. The α-crystal silver iodide has a strong bonding force with silver because silver atoms are disordered between iodine atoms. If a silver thin film is etched by utilizing this property and high ion conductivity and easy diffusion, a fine silver pattern can be formed with high accuracy and efficiency.
[0010]
In the method for manufacturing an electro-optical device or a semiconductor device according to the present invention, hydrogen iodide (HI), methyl iodide (C ₂ H _Five I), propyl iodide (C _Three H ₇ I) or butyl iodide (C _Four H ₉ Any one of iodine hydrocarbon compounds having a relatively low molecular weight and a low boiling point such as I) can be suitably used.
This is because these iodine compounds are excellent in stability and can be easily dissociated to use active iodine.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The method for manufacturing an electro-optical device or a semiconductor device according to the present invention creates a thin film laminated structure according to each design structure and etches them by etching in the same manner as a method for manufacturing an electro-optical device or a semiconductor device that is generally performed. By patterning, a structure having a necessary shape is formed, and as a method for forming a silver pattern at that time, the silver thin film is dry-etched using iodine compound vapor. Therefore, here, the description will focus on the silver pattern forming method.
First, a silver thin film is formed at a predetermined position of the laminated structure. The method for forming the silver thin film is not particularly limited, and physical vapor deposition (PVD) such as vapor deposition and sputtering, ion plating, chemical vapor deposition (CVD), and the like can be used. The silver thin film is generally formed on the entire surface of the substrate.
Next, using a photoresist pattern formed on the silver thin film by lithography as a mask, a silver circuit pattern such as a silver reflective layer having a predetermined shape, fine electrodes or wiring is formed by dry etching using iodine compound vapor. .
[0012]
The dry etching method is not particularly limited, and normal plasma etching (Plasma Etching: PE), reactive ion etching (RIE), inductively coupled plasma etching (ICP), or the like can be used. In particular, in the electro-optical device or semiconductor device manufacturing method of the present invention, the ICP method improves the controllability by supplying the high-frequency power for plasma generation and the high-frequency power for drawing ions into the substrate independently of each other. Therefore, it is convenient because a bias can be easily applied to atoms that are difficult to fly, and a high-density plasma can be obtained.
[0013]
Examples of gases introduced into the reaction chamber include hydrogen iodide (HI) and methyl iodide (CH _Three I), ethyl iodide (C ₂ H _Five I), propyl iodide (C _Three H ₇ I) or butyl iodide (C _Four H ₉ An iodine compound such as I) is used. This is because these compounds have a relatively small molecular weight and are stable, have a relatively low boiling point, easily obtain a vapor, and can easily dissociate and use active iodine species. It is also easy to obtain.
By the way, hydrogen iodide has a molecular weight of 127.9 and a boiling point of −35 ° C., methyl iodide has a molecular weight of 142 and a boiling point of 42.5 ° C., ethyl iodide has a molecular weight of 156, a boiling point of 72 ° C., and propyl iodide. Has a molecular weight of 170 and a boiling point of 102 ° C., and butyl iodide has a molecular weight of 184 and a boiling point of 131 ° C.
The iodine compound may be used as a single vapor, but may be used as a mixed gas in which 10% or more of the iodine compound is added using hydrogen or argon as a carrier gas. When used as a mixed gas, the etching proceeds gently, and a silver pattern with higher accuracy can be obtained without causing damage to the lower layer.
When a substrate on which a pattern using a photoresist as a mask is formed on a silver thin film is inserted into a chamber of a dry etching apparatus and vapor of the iodine compound is introduced into the chamber and high frequency power is applied, the iodine compound is dissociated. Active iodine is generated and reacts with the silver in the exposed portion of the substrate to produce silver iodide, and the silver thin film is removed by etching.
[0014]
At this time, the substrate temperature is heated to 147 ° C. or higher to produce α-phase silver iodide. As described above, silver iodide undergoes a phase transition from the β phase of the wurtzite structure to the α phase at 147 ° C. as a boundary. 14 and 15 show the crystal structure of silver iodide before and after the phase transition (see Burns, “Solid Physics” p. 54, published by Tokai University Press). FIG. 14 shows a β-phase crystal structure that is stable at temperatures below 147 ° C., and FIG. 15 shows an α-phase crystal structure that is stable at temperatures above 147 ° C. In the dry etching of silver, the α-phase silver iodide shown in FIG. 15 is effective, and the black circle (6d position), white small circle (12d position), triangle ( Ag atoms enter the disorder at the position indicated by (24h position). Since this α-phase type silver iodide has high ionic conductivity and is easily diffused, when used as an etchant, it becomes possible to improve the uniformity of etching and increase the etching efficiency.
[0015]
(First embodiment)
An example of manufacturing a reflective liquid crystal display device by the method of the present invention will be described with reference to the drawings.
1 to 8 are sectional process diagrams in the case of manufacturing a reflective liquid crystal display device by the method of the present invention. In the first embodiment, a liquid crystal display device having a reflective layer made of a silver thin film in each pixel electrode portion in an active matrix driving system having two types of TFTs and one storage capacitor is taken as an example. explain. The figure shows a so-called element substrate provided with a drive element among a pair of opposing substrates.
In the following drawings, the scale is changed for each layer and each member in order to display each layer and each member in a size that can be recognized on the drawing.
[0016]
First, as shown in FIG. 1, an insulating layer 32 made of silicon nitride 32 and silicon oxide 33 is formed on a glass substrate 31, and an amorphous silicon layer (not shown) is formed thereon. Thereafter, the amorphous silicon layer is subjected to a heat treatment such as laser annealing to recrystallize the amorphous silicon layer into a crystalline polysilicon layer, and patterned by etching to form two TFT formation positions. An island-shaped polysilicon layer 40 is formed at one storage capacitor forming position. The thickness of the polysilicon layer 40 is, for example, about 50 nm. Next, a gate insulating layer 30 is formed on the entire surface of the substrate. The thickness of the gate insulating layer 30 is, for example, about 100 to 150 nm. This process is similarly performed in the display area 1 and the peripheral area 2.
Next, the position where the N-channel TFT is formed in the display area 1 and the entire area of the peripheral area 2 are masked with a resist 41 such as polyimide. Then, after masking both the display region 1 and the peripheral region 2, the portion not covered with the mask is subjected to, for example, PH as a donor. _Three / H ₂ Ions are doped into the polysilicon layer 40 through the gate insulating layer 30. The doping conditions at this time are, for example, ³¹ The dose amount of P is 3 × 10 ¹⁴ ~ 5x10 ¹⁴ / Cm ² The energy is about 80 KeV (see FIG. 2).
[0017]
Next, PH _Three / H ₂ After doping with ions, the resist 41 is peeled off, gate electrodes 8 and 9 are then formed at positions where two TFTs are to be formed, and a capacitor electrode 23 is formed at a position where one storage capacitor is to be formed. In order to form the gate electrodes 8 and 9 and the capacitor electrode 23, a silver thin film having a thickness of about 50 to 300 nm is vacuum deposited or sputtered on the entire surface of the substrate, and then the silver thin film is etched into a predetermined shape. That is, a photoresist mask pattern is formed at the position of the gate electrode and the capacitor electrode on the silver thin film using a lithography technique, loaded into a dry etching apparatus, and dried into a predetermined shape using an iodine compound vapor. The gate electrodes 8 and 9 or the capacitor electrode 23 are formed. At the same time, data lines and scanning lines (not shown) can be formed on the substrate in plan view.
For example, dry etching uses methyl iodide (CH 2) as a reaction gas using an ICP apparatus. _Three I) Argon is used as the carrier gas. The mixing ratio of methyl iodide and argon is preferably about 1: 1. The substrate temperature is 147 ° C. or higher, preferably 180 ° C. to 200 ° C. The applied power requires a frequency of about 13.56 MHz and about 5 kW.
[0018]
Next, after forming the gate electrodes 8 and 9 and the capacitor electrode 23, again using the gate electrodes 8 and 9 and the capacitor electrode 23 as a mask, the portion not covered with the mask is again PH. _Three / H ₂ Doping with ions. The doping conditions at this time are, for example, ³¹ The dose amount of P is 4-5 × 10 ¹⁴ / Cm ² About 60 KeV is required as energy. As a result, N polysilicon is formed on the polysilicon layer 40 immediately below the gate electrodes 8 and 9 and the capacitor electrode 23. ^- Regions are formed (see FIG. 3).
Next, as shown in FIG. 4, an interlayer insulating film 35 made of silicon oxide having a thickness of about 20 nm is formed on the entire surface of the substrate, masked with a resist 42 at a position where an N-channel TFT in the display region 1 is formed, and then masked. B as acceptor in the part not covered with ₂ H ₆ / H ₂ Doping with ions. The doping conditions at this time are, for example, ¹¹ B dose is 5E ¹⁴ / Cm ² As described above, energy of about 25 to 30 KeV is required. Through this process, the source region and the channel region of the TFT are formed.
[0019]
Next, as shown in FIG. 5, the entire substrate is covered with an interlayer insulating film 38 made of silicon oxide oxide having a thickness of about 800 nm, and then contact holes are opened at positions to be the source electrode and the train electrode of the TFT and to be the capacity electrode. To do.
Next, a silver thin film (not shown) is formed on the entire surface of the substrate including the contact holes. As described above, vapor deposition or sputtering can be used to form the silver thin film. After forming a silver thin film on the entire surface of the substrate, a resist and mask treatment is applied to the electrode position of each contact hole using photolithography technology, and the silver thin film is patterned again by dry etching using an iodine compound as a reaction gas, The source electrode 11 and drain electrode 12 of the P-channel TFT 61, the source electrode 13 and drain electrode 14 of the N-channel TFT 21, and the lead-out portion 24 of the storage capacitor 22 are formed (see FIG. 6). The dry etching method for the silver thin film may also be as described above.
[0020]
Next, as shown in FIG. 7, a protective film 44 made of silicon nitride having a thickness of about 20 nm is formed on the entire surface of the substrate including the electrodes, and a photosensitive acrylic resin film 45 is formed thereon with a thickness of about 500 nm. The photosensitive acrylic resin film 45 has irregularities on the surface so that incident light is irregularly reflected. In order to form the surface irregularities, for example, a photosensitive acrylic resin film is formed in two layers, and after forming the first photosensitive acrylic resin film, small holes are provided in the photosensitive acrylic resin film at appropriate intervals, A photosensitive acrylic resin film may be formed again from above. After the formation of the two-layer photosensitive acrylic resin film, the small hole portion of the first film becomes a concave portion, the non-small hole portion becomes a convex portion, and the surface of the two-layered photosensitive acrylic resin film is an uneven surface. It becomes. Next, a contact hole is opened in the drain electrode 14 that communicates with the pixel electrode.
Next, as shown in FIG. 8, a silver thin film (not shown) serving as a reflective layer is formed on the surface of the photosensitive acrylic resin film 45 having irregularities. As described above, the silver thin film can be formed by vapor deposition or sputtering. Next, the silver thin film is patterned so as to remain only in the pixel region by dry etching using iodine compound vapor, thereby forming the reflective layer 50. Also in this case, the dry etching method for the silver thin film may be as described above.
In this embodiment, an example in which a silver pattern is used for the reflective layer and each electrode has been described. However, it is needless to say that a signal line and a data line can be formed using silver having a very low specific resistance by a similar method.
[0021]
Finally, for example, an ITO film to be a pixel electrode is formed on the substrate surface, and patterned into a predetermined shape to form the pixel electrode 52.
In this way, a so-called element substrate for a liquid crystal display device having an active matrix driving type driving element having two kinds of TFTs and one storage capacitor and having a reflective layer made of a silver thin film in each pixel electrode portion is provided. can get. A liquid crystal display panel is completed by disposing a counter substrate, which is the other substrate, on the side of the element substrate facing the pixel electrode 52 and enclosing liquid crystal between the two substrates.
The liquid crystal display panel obtained in this way has a reflective layer made of a silver thin film with high light reflectivity, has electrodes and wiring sections with low electrical specific resistance, has a clear screen, and has a high response speed. Therefore, it can be used for various electro-optical devices such as a mobile phone, a clock, an information processing device, or a projection display device.
[0022]
(Second Embodiment)
FIGS. 9 to 13 are sectional process diagrams in the case of manufacturing a monolithic semiconductor device for memory according to the second embodiment of the present invention.
First, as shown in FIG. 9, a silicon oxide base insulating film (not shown) is formed on a silicon substrate 101. Next, after forming a protective film made of a silicon nitride film (not shown) on the half of the substrate, it is oxidized to form a LOCOS (Local Oxidation of Silicon) film 102 in a portion without the protective film made of the silicon nitride film. Next, the protective film and the base insulating film of silicon oxide are removed. Although the oxide film remains in the portion of the LOCOS film 102, the silicon substrate 101 is exposed in the portion without the LOCOS film 102. In this state, boron ions (B ⁺ ) Is doped by ion implantation to form a P well region 103.
Next, a gate insulating film 106, a doped polysilicon film 107, and an insulating film 108 are sequentially formed and laminated on the entire surface of the substrate, and then the three layers are sequentially etched into a predetermined shape to form four island patterns. To do. Next, a thick silicon oxide film 110 is formed on the entire surface of the substrate, and the silicon oxide film 110 is etched back to form sidewalls 111 around the four island patterns.
Further, phosphor ions (P ^- ) Is ion-implanted into the portion of the substrate 101 not covered with the oxide film, n ⁺ A diffusion region 113 is formed.
[0023]
Next, as shown in FIG. 10, a TEOS (Tetraethyl orthosilicon) film 114 is formed on the entire surface of the substrate, and a contact hole 115 is provided in the TEOS film 114 using a photolithography technique. Thereafter, a doped polysilicon film 117 is formed on the entire surface of the substrate, and the doped polysilicon film 117 is patterned using a photolithography technique to form a lower electrode 118 made of doped polysilicon.
Next, after forming a thin insulating film (not shown) on the surface of the lower electrode 118, a doped polysilicon film (not shown) to be the upper electrode of the memory cell is formed, and patterning is performed using a photolithography technique. As shown in FIG. 11, the upper electrode 120 of the memory cell is formed. Further, an interlayer insulating film composed of two layers of a TEOS film 122 and a BPSG film 124 is formed, and a contact hole 123 is formed in the interlayer insulating film using a photolithography technique.
[0024]
Next, as shown in FIG. 12, a doped polysilicon film 125 of a bit line including the contact hole 123 is formed, an interlayer insulating film 126 is formed thereon, and a thickness of about 50 to 300 nm is further formed thereon. The silver thin film 130 is formed by vacuum deposition or sputtering. Further, a photoresist mask pattern is formed at a predetermined position on the silver thin film 130 by using a lithography technique, loaded into a dry etching apparatus, and dry etching using iodine compound vapor to form the silver thin film in a predetermined shape. The silver wiring 131 is formed by patterning.
For example, dry etching uses methyl iodide (CH 2) as a reaction gas using an ICP apparatus. _Three I) Argon is used as the carrier gas. The mixing ratio of methyl iodide and argon is preferably about 1: 1. The substrate temperature is 147 ° C. or higher, preferably 180 ° C. to 200 ° C. The applied power requires an upper electrode frequency of 13.56 MHz and about 5 kW, and a lower electrode frequency of about 4 MHz and 5 kW.
[0025]
Next, as shown in FIG. 13, an interlayer insulating film 133 is formed on the entire surface of the substrate, the surface is planarized by etch back, and a silver thin film having a thickness of about 50 to 300 nm is formed again by vacuum evaporation or sputtering. To do. Further, a photoresist mask pattern is formed in a predetermined position on the silver thin film in a direction orthogonal to the previous silver wiring 131 by using a sommographic technique, and loaded into a dry etching apparatus using an iodine compound vapor. Then, a silver wiring 135 having a predetermined shape is formed by dry etching. The method for forming the silver thin film and dry etching the silver thin film may be the same as that for forming the silver wiring 131.
Finally, a passivation film 136 made of silicon nitride is formed on the silver wiring 135 to obtain a monolithic semiconductor device for memory.
Since the semiconductor device obtained in this manner uses silver having a low specific resistance for circuit wiring, a high-performance semiconductor device with high signal transmission speed, low heat generation and low power consumption can be obtained. . Moreover, since it can be manufactured by a dry process, the equipment can be manufactured relatively easily and efficiently, and the economic effect is great.
[0026]
【The invention's effect】
The liquid crystal display panel obtained by the present invention has a reflective layer made of a silver thin film having a high light reflectivity, has an electrode and a wiring part having a low electrical specific resistance, has a clear screen and a high response speed, and has an extremely high quality. Since a display screen can be obtained, it can be used for various electro-optical devices such as a mobile phone, a clock, an information processing device, or a projection display device.
In addition, since the semiconductor device obtained by the present invention uses silver having a low specific resistance for an electrode or circuit wiring, a high-performance semiconductor device having a high signal transmission speed, a small amount of heat generation, and low power consumption. can get. In addition, a high-definition circuit pattern can be manufactured by a dry process, and the equipment can be manufactured relatively easily and efficiently.
As described above, the method for manufacturing an electro-optical device or a semiconductor device according to the present invention can perform etching of a silver thin film excellent in uniformity with high efficiency, and is in line with the trend of dry manufacturing processes.
[Brief description of the drawings]
FIG. 1 is a process cross-sectional view illustrating a method for manufacturing an electro-optical device according to the invention.
FIG. 2 is a process cross-sectional view subsequent to FIG. 1;
FIG. 3 is a process cross-sectional view subsequent to FIG. 2;
FIG. 4 is a process cross-sectional view subsequent to FIG. 3;
FIG. 5 is a process cross-sectional view subsequent to FIG. 4;
FIG. 6 is a process cross-sectional view subsequent to FIG. 5;
FIG. 7 is a process cross-sectional view subsequent to FIG. 6;
FIG. 8 is a process cross-sectional view subsequent to FIG. 7;
FIG. 9 is a process cross-sectional view illustrating the method for manufacturing a semiconductor device of the present invention.
FIG. 10 is a process cross-sectional view subsequent to FIG. 9;
FIG. 11 is a process cross-sectional view subsequent to FIG. 10;
FIG. 12 is a process cross-sectional view subsequent to FIG. 11;
FIG. 13 is a process cross-sectional view subsequent to FIG. 12;
FIG. 14 is a diagram showing the structure of β-phase silver iodide.
FIG. 15 is a diagram showing the structure of α-phase silver iodide.
FIG. 16 is a perspective view showing a liquid crystal display device.
17 is a cross-sectional view taken along line AA ′ of FIG.
[Explanation of symbols]
8, 9 ... Gate electrode, 21 ... N-channel TFT, 22 ... Storage capacitor, 23 ... Capacitance electrode, 30 ... Insulating layer, 40. ..... Polysilicon layer, 50 ... Reflective layer, 52 ... Pixel electrode, 61 ... P-channel TFT, 70 ... Light source, 80 ... Natural light, 31 ... substrate, 101 ... substrate, 102 ... LOCOS film, 103 ... P well region, 111 ... side wall, 113 ... ..N ⁺ Diffusion region, 114... TEOS film, 118... Lower electrode, 120... Upper electrode, 122... TEOS film, 124. 135: Silver wiring, 140: Liquid crystal, 144: Pixel electrode, 148: TFD, 150: Liquid crystal display, 154: Reflective layer, 156 ... Light shielding layer,

Claims (3)

A liquid crystal is held between a pair of substrates, and electrodes are formed on opposing surfaces of each substrate, and a reflective layer made of a silver (Ag) thin film is formed between the electrodes of at least one of the substrates. An electro-optical device manufacturing method comprising:
After the silver thin film is formed , the silver thin film is dry-etched using an iodine (I) compound vapor to form a silver reflective layer pattern having a predetermined shape ,
When etching the silver thin film into a predetermined shape using an iodine compound vapor, the substrate is maintained at a temperature of 147 ° C. or more, and silver iodide is phase-transformed into an α phase for etching. A method for manufacturing an electro-optical device. A method of manufacturing an electro-optical device in which liquid crystal is held between a pair of substrates, and an electrode made of a silver (Ag) thin film or a circuit wiring made of a silver (Ag) thin film is formed on at least one opposing surface of each substrate Because
After the silver thin film is formed , the silver thin film is dry-etched using an iodine (I) compound vapor to form a silver electrode pattern or a silver circuit wiring pattern having a predetermined shape ,
When etching the silver thin film into a predetermined shape using an iodine compound vapor, the substrate is maintained at a temperature of 147 ° C. or more, and silver iodide is phase-transformed into an α phase for etching. A method for manufacturing an electro-optical device. The iodine compound is hydrogen iodide (HI), methyl iodide (CH ₃ I), ethyl iodide (C ₂ H ₅ I), propyl iodide (C ₃ H ₇ I) or butyl iodide (C ₄ H _9). 3. The method of manufacturing an electro-optical device according to claim 1, wherein the method is any one of I).

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