CN1146038C - A method for manufacturing the same - Google Patents

Abstract

To crystallize an amorphous silicon film by coasting the surface of a substrate, on which an amorphous silicon film is formed, with a solution containing a catalytic element and forming an amorphous silicon film thereon under that state before heat treatment. An acetate solution added with nickel is prepared and dripped onto the surface of a silicon oxide film 12 which is then subjected to spin drying. The step for coating with nickel solution is performed one to several times thus forming a layer containing nickel on the surface of the silicon oxide film 12 after spin drying. In this regard, nickel in the layer is spread into an amorphous silicon film 14 during a subsequent heating process (heating at 550 deg.C for 4 hours) and serves as a catalyst for accelerating the crystallization. After the coating process, prebaking is performed in a nitrogen atmosphere.

Description

Semiconductor device and manufacture method thereof

The present invention relates to adopt and have semi-conductive semiconductor device of crystalline state and manufacture method thereof.

It is known adopting the thin-film transistor (hereinafter referred TFT) of thin film semiconductor.TFT forms thin film semiconductor on substrate, constitute with this thin film semiconductor again.TFT has been used to various integrated circuits, particularly electro-optical device, to receiving much concern as the switch element of each pixel setting of active array type LCD and the driving element that is formed at peripheral circuit.

As the thin film semiconductor that is used for TFT, it is easy adopting amorphous silicon film, yet, there is the problem of its electric property difference.For improving the characteristic of TFT, preferably use silicon fiml with crystalline state.Silicon fiml with crystalline state is called the silicon of the silicon of many crystallizations, poly-silicon and micro-crystallization etc.For obtaining having the silicon fiml of crystalline state, at first form amorphous silicon film, by heating, make its crystallization then.

The crystallization by heating requires heating-up temperature more than 600 ℃, the time of cost more than 10 hours, exists to be difficult to use glass substrate to do the problem of substrate.For example, the glass deformation point that is used for Corning 7059 glass of active array type LCD is 593 ℃, considers the large tracts of landization of substrate, when being heated to more than 600 ℃, exists problem.

According to studies confirm that of present inventors,, 550 ℃ of heat treated 4 hours, can carry out crystallization then at amorphous silicon film surface deposition micro-nickel, palladium and lead and other elements.

For introducing above-mentioned trace element (promoting the catalyst elements of crystallization), can utilize plasma treatment, evaporation and ion injection method.Plasma treatment is in plate or cylinder type plasma CVD apparatus, and as electrode, in nitrogen or hydrogen atmosphere, the product plasma adds catalyst elements to the method on amorphous silicon film surface with the material that contains catalyst elements.

But, in semiconductor,, use this semi-conductive device reliability and electrical stability because use this semiconductor to damage if it is inappropriate having excessive above-mentioned element.

That is,, wish preferably not mix in the silicon of crystallization though in the crystallization of amorphous silicon film, need above-mentioned nickel etc. to promote the element (catalyst elements) of crystallization.For reaching this purpose, be chosen in the crystallized silicon more inactive element and make catalyst elements, make the required catalyst elements amount of crystallization few as far as possible, must carry out crystallization with minimum limiting the quantity of.So the addition of catalyst elements is accurately introduced on control ground.

To make the situation of catalyst elements with nickel, to the formation of amorphous silicon film, with plasma processing add the crystalline state silicon fiml of nickel making, and crystallisation procedure does etc. further investigate, confirmed following item.

(1) before nickel being introduced occasion on the amorphous silicon film with plasma treatment, being found heat-treating, nickel has invaded the quite dark position in the amorphous silicon film.

(2) original nucleus is produced by the surface of introducing nickel.

(3) promptly use vapour deposition method under the situation that forms the nickel film on the amorphous silicon film, also can with the situation of carrying out plasma treatment in the same manner, crystallization takes place.

In view of the above fact, think that the nickel of introducing with plasma treatment is not to work effectively.That is, introduce excessive nickel, then have the nickel that does not fully work.Therefore, think that just the contact point (face) of silicon and nickel just works in the low temperature crystallization process.Also think that nickel must present fine state of atom as much as possible and scatter.Promptly think and " require at the amorphous silicon film near surface, in the scope that can make low temperature crystallizationization, introduce the nickel that is the state of atom dispersion of low concentration as far as possible.”

As the method for only introducing denier nickel at the amorphous silicon film near surface, in other words, only introduce the method that promotes crystallization denier catalyst elements at the amorphous silicon film near surface, though can enumerate vapour deposition method, but vapour deposition method is controlled bad, so there is the problem of the introducing amount that is difficult to strict control catalyst element.

The present invention's purpose is, by the heat treatment below 600 ℃, uses catalyst elements to make the thin film silicon semiconductor with crystalline state, satisfies following requirement:

(1) amount of catalyst elements is introduced in control, makes this amount be minimum limiting the quantity of;

(2) boost productivity.

The present invention for achieving the above object, adopts following measure, obtains to have the silicon fiml of crystalline state.

The compound that keeps making the catalytic elements monomer that promotes the amorphous silicon film crystallization or containing aforementioned catalyst elements contacts with this amorphous silicon film, make aforementioned catalyst elements monomer or containing under the compound and aforementioned amorphous silicon film state of contact of aforementioned catalytic elements, implement heat treated, make aforementioned amorphous silicon film crystallization.

Specifically, make the solution that contains catalyst elements be coated on substrate (, also the claiming substrate in this manual) surface of amorphous silicon film to be formed even form diaphragm on the surface; under this state; form amorphous silicon film at substrate surface,, realize the crystallization of amorphous silicon film again through heat treated.

The present invention is characterised in that, introduces and the contacted catalyst elements in amorphous silicon film surface.This technology is very important to the control of the amount of catalyst elements.

Another is characterised in that, adopts the crystalline state silicon fiml that so forms can constitute the active area that has PN, PI, NI and other electrical junction at least.As semiconductor device, can be used for thin-film transistor (TFT), diode, photoelectric sensor.

Owing to adopt structure of the present invention, can obtain principal advantages shown below.

(a) thus can be the in advance strict control of the concentration of catalytic elements in solution can improve degree of crystallinity, also make amount of element few as far as possible.

(b) as long as the amorphous silicon film surface contacts with solution, catalytic elements can be determined according to the concentration of catalytic elements in the solution to the introducing amount of amorphous silicon film.

(c) because the catalytic elements that contacts with the amorphous silicon film surface is mainly used in crystallization, then can introduce catalytic elements by required MIN concentration.

Coating contains the solution that promotes the crystallization element on the substrate of amorphous silicon film to be formed, as for solution, can use the aqueous solution and organic solvent solution etc." containing " herein comprises the meaning of two aspects, and (1) is the meaning that the meaning that compound comprises and (2) comprise simply dispersedly.

Be selected from water, alcohol, acid, ammonia isopolarity solvent about comprising the solvent of catalyst elements, can using.

Use nickel as catalyst, in polar solvent, comprise under the situation of nickel, make nickel be nickel compound and introduce.Can be selected from representational nickelous bromide, nickel acetate, nickel oxalate, nickelous carbonate, nickel chloride, nickel iodide, nickel nitrate, nickelous sulfate, nickel formate, nickel acetylacetonate, 4-cyclohexyl butyric acid nickel, nickel oxide, nickel hydroxide about nickel compound.

In addition, about containing the solvent of catalytic elements, can select non-polar solven such as benzene,toluene,xylene, carbon tetrachloride, chloroform, ether for use.

Under this situation, make nickel be nickel compound and introduce.As this nickel compound, can select representational nickel acetylacetonate, 2 ethyl hexanoic acid nickel for use.

In addition, it also is favourable adding surfactant in containing the solution of catalytic elements.So just improved adhesiveness, realized control adsorptivity to coated.This surfactant can be coated on coated in advance.

Using under the situation of nickel monomer as catalytic elements, it must be dissolved in and make solution in the acid.

In sum, use the example allow as the consoluet solution of nickel of catalytic elements, the not exclusively situation of dissolving of nickel is also arranged certainly, also can use and to be dispersed in emulsion material in the decentralized medium by the nickel monomer or by the powder that nickel chemical combination constitutes though have.

The explanation of front is arranged again, and it also is identical that the material of use except that nickel made catalyst elements.

Using nickel as the catalyst elements that promotes crystallization, doing to contain with polar solvent such as water under the situation of solution solvent of nickel, when directly applying this kind solution on the substrate surface that is forming amorphous silicon film, amorphous silicon film can repel this solution.In the case, can form the following thin oxide film of one deck 100 earlier, coating thereon contains the solution of catalyst elements, and solution is coated with equably.In addition, adding a kind of surfactant in solution, also is favourable with this method of improving wetability.Have, for the structure of the TFT that forms on glass substrate, formation silicon oxide film and silicon nitride film have been known as the measure of counterdie on glass substrate surface, in the case, can directly apply solution again.

In addition, when the toluene solution that uses non-polar solven such as 2 ethyl hexanoic acid nickel makes solution, can not form the counterdie oxide-film, directly apply solution.In the case, applying a kind of material in advance, is effective as the adhesive that uses when applying glue against corrosion.

Catalyst elements amount contained in the solution is decided according to the kind of solution.Rough says that to the content of nickel in the solution, hope is preferably 1ppm-50ppm (weight ratio that catalyst elements is all to solution) of 1ppm～200ppm.This is to finish nickel concentration and the determined value of hydrofluoric acid resistance in film afterwards by crystallization.

In addition, according to selecting coating to contain the solution of catalyst elements, can selectively carry out crystalline growth.Particularly in the case, can carry out crystalline growth along roughly parallel direction towards the zone of uncoated solution from the zone of coating solution with the silicon fiml face.The edge is called the transverse crystallizing growth district in this manual with the zone that the direction of this silicon fiml face almost parallel is carried out crystalline growth.

Also provable, this concentration of catalytic elements in zone of laterally carrying out crystalline growth is low.Though the active layer district that adopts the crystalline state silicon fiml to make semiconductor device is favourable, the impurity concentration in active layer generally with lower for well.So in the making of device, the active area that adopts above-mentioned zone of laterally carrying out crystalline growth to form semiconductor device is favourable.

In addition in the present invention, because introduced the catalytic elements that promotes crystallization with the semi-conductive interface of thin film silicon that on this face, forms, then can reduce the concentration of the catalytic elements on the thin film silicon semiconductor surface of crystallization at the face that is formed.

Generally, though TFT has the structure of insulated-gate type field effect transistor, in insulated-gate type field effect transistor, the interface of channel formation region territory and gate insulating film and the zone of near interface are very important.

For the insulated-gate type field effect semiconductor device,, make the characteristic of insulated-gate type field effect transistor be subjected to very big infringement owing to have interface energy level at the interface and the near zone thereof of channel formation region and gate insulating film.Think that movably ion and impurity are the key factors that forms this energy level.Thereby form under the situation of TFT of structure of gate insulating film make adopting, wish not allow existence such as impurity as far as possible on the silicon fiml surface at silicon fiml.

Also have the present invention, in the gamut because of the silicon fiml behind crystallization, make to promote the catalyst elements concentration of crystallization to reduce as best one can, this also is very favourable.

In addition, adopting under the situation of the inventive method, do not finding the CONCENTRATION DISTRIBUTION of seen depth direction catalytic elements at processed under the situation of using plasma treatment, thereby the unwanted diffusion of catalytic elements does not take place when heat treated.

In aforesaid the present invention, owing to can lower the catalyst elements concentration on the silicon fiml surface that is present in crystallization as far as possible, thereby can form the TFT that not influenced by this kind catalytic elements as far as possible.That is, introduce with silicon fiml down and the catalyst elements of contacted promotion crystallization, can realize the influence minimum structure of catalyst elements to the electronic device characteristics of utilizing the crystal silicon film surface.

In the present invention, though adopt nickel, can obtain very significant effect, as for other available catalyst elements and kind, can select Ni, Pd, Pt, Cu, Ag, Au, In, Sn, P, As and Sb for use as catalytic elements.In addition, also can utilize one or more elements of from VIII family element, IIIb, IVb, Vb element, selecting.

Using iron (Fe) to do under the situation of catalytic elements, can use from known molysite material as its compound, for example, ferrous bromide (FeBr ₂6H ₂O), ferric bromide (FeBr ₃6H ₂O), ferric acetate (Fe (C ₂H ₃O ₂) ₃XH ₂O), frerrous chloride (FeCl ₂4H ₂O), iron chloride (FeCl ₃6H ₂O), ferric flouride (FeF ₃3H ₂O), ferric nitrate (Fe (NO ₃) ₃9H ₂O), ferrous phosphate (Fe ₃(PO ₄) ₂8H ₂O), ferric phosphate (FePO42H ₂O) material of selecting in.

Using under the situation of cobalt (Co) as catalytic elements,, can use from known cobalt salt material, for example cobaltous bromide (CoBr6H as its compound ₂O), cobalt acetate (Co (C ₂H ₃O ₂) ₂4H ₂O), cobalt chloride (COCl ₂6H ₂O), cobaltous fluoride (CoF ₂XH ₂O), cobalt nitrate (Co (NO ₃) ₂6H ₂O) material of selecting in.

Doing under the situation of catalytic elements with ruthenium (Ru), can use known ruthenium salt material as its compound, as ruthenic chloride (RuCl ₃H ₂O).

Use rhodium (Rh) as the catalytic elements situation under, as its compound, can use known rhodium salt material, as radium chloride (RhCl ₃3H ₂O).

Using palladium (Pd) to do under the situation of catalytic elements,, can use known palladium salt material, as palladium bichloride (PdCl as its compound ₂2H ₂O).

Using osmium (Os) to do under the situation of catalytic elements,, can use known osmium salt material, as osmium chloride (OsCl as its compound ₃).

Using iridium (Ir) to do under the situation of catalytic elements,, can use from known iridium salt material, as iridous chloride (Ircl as its compound ₃3H ₂O), iridic chloride (IrCl ₄) in the material selected.

Using platinum (Pt) to do under the situation of catalytic elements,, can use known platinum salt material, for example platinum chloride (PtCl as its compound ₄5H ₂O).

Using copper (Cu) to do under the situation of catalytic elements,, can use from copper acetate (Cu (CH as its compound ₃COO) ₂), copper chloride (CuCl ₂2H ₂O), copper nitrate (Cu (NO ₃) ₂3H ₂O) material of selecting in.

Using gold (Au) to do under the situation of catalytic elements,, can use from gold trichloride (AuCl as its compound ₃XH ₂O), chlorauride salt (AuHCl ₄4H ₂O), tetrachloro gold sodium (AuNaCl ₄2H ₂O) select material in.

In addition, introduce the method for catalytic elements, be not limited to use solution such as the aqueous solution and alcohol, also can use the material that contains catalytic elements widely.For example, can use the metallic compound that contains catalytic elements and oxide etc.

The drawing simple declaration

Fig. 1 represents the manufacturing process steps of embodiment.

Fig. 2 represents the manufacture craft of embodiment.

Fig. 3 represents the manufacture craft of embodiment.

The number in the figure explanation

11 ... glass substrate 12 ... silicon oxide film

13 ... nickeliferous acetic acid solution film 14 ... silicon fiml

104 ... active layer 105 ... silicon oxide film

106 ... gate electrode 107 ... oxide skin(coating)

108 ... source/drain region 109 ... leakage/source region

110 ... interlayer dielectric (silicon oxide film) 111 ... pixel electrode (ITO)

112 ... electrode 113 ... electrode

Embodiment 1

In the present embodiment,, be coated on the glass substrate, form amorphous silicon film then,, make its crystallization by heat treated with promoting the catalyst elements of crystallization to be contained in the aqueous solution.

In the present embodiment, use Corning 7059 glass to make substrate, it is of a size of 100mm * 100mm.

Fig. 1 represents the manufacturing process steps of present embodiment.At first, on glass substrate 11, form the thick silica counterdie 12 of 2000 with sputtering method.Then, carry out hydrofluoric acid treatment, pollute and natural oxide film to remove.Polluting under the insignificant situation, omit this step process also can, from not waiting to say.

Then, be produced on the acetate solution that has added nickel in the acetate solution.The concentration of nickel is 25ppm.Then, the acetate solution of 5ml is dropped in the surface of silicon oxide film 12, this state was kept 5 minutes.Dry (2000rpm, 60 seconds) (Figure 1A) with spin coater then.

The concentration of nickel in acetic acid solution, the scope of the most handy 1ppm～50ppm.

Carry out 1 time～nickel solution coated technique repeatedly, after drying, on the surface of silicon oxide film 12, evenly form the nickeliferous film of number ～hundreds of .In the case, the nickel in this layer is diffused in the amorphous silicon film in follow-up heating process, as the catalyst that promotes crystallization.Also have, so-called here layer needn't one be shaped as totally continuous film.

After the above-mentioned solution coating, under 400 ℃ temperature, carry out prebake in the blanket of nitrogen.Carry out this step process, the solution that is adsorbed in silicon oxide film 12 surfaces is decomposed.Owing to carry out this step process, can prevent membranous coarse at the amorphous silicon film 14 that forms subsequently.The temperature of prebake will change according to solutions employed kind in the coated technique certainly.

Then, form the thick amorphous silicon film 14 of 100～500 by plasma CVD method and LPCVD method.At this, be the amorphous silicon film 14 that forms thick 1000 with plasma CVD method.

Then, use heating furnace.In 550 ℃ blanket of nitrogen, heat-treated 4 hours.As a result, can obtain to be formed at the silicon fiml with crystalline state 14 on the substrate 11.

Above-mentioned heat treated can be carried out in the temperature more than 450 ℃, but temperature is low, and must extend heating time, and productivity ratio is reduced.In addition, make temperature more than 550 ℃ the time, just outstanding as the thermal endurance problem of the glass substrate of substrate.

Embodiment 2

Present embodiment is that catalyst elements nickel is dissolved in the non-aqueous solution alcohol, is coated in the example on the amorphous silicon film.In the present embodiment, use the compound of nickel acetylacetonate, this compound is contained in the alcohol as nickel.And the concentration that makes nickel makes required concentration.

Later technology identical with shown in the embodiment 1.In addition, the roughly process of manufacture craft is same as shown in Figure 1.The following describes concrete condition.At first, prepare the nickel acetylacetonate as nickel compound, this thing dissolves in the alcohol, because decomposition temperature is low, when therefore heating in the crystallization process process, can be decomposed easily.

In addition, be to use ethanol as alcohol.At first nickel acetylacetonate is converted into the amount of nickel in ethanol, is adjusted to 50ppm, make the solution that contains nickel.

This solution of coating on silica counterdie 12.On the silica counterdie, apply solution, compare, lack some and also can with the situation of the aqueous solution that uses embodiment 1.This is because the contact angle cause littler than the contact angle of water of ethanol.Here, to the area of 100mm * 100mm, drip 2ml.

Then, keep 5 minutes in this state.Then, use spin coater to dry.At this moment, spin coater was with 1500rpm rotation 1 minute.After this, form amorphous silicon film,, carry out crystallization 550 ℃ of heat treated 4 hours.This just obtains the silicon fiml of crystalline state.

Embodiment 3

Present embodiment relates to, and catalytic elements nickel monomer is dissolved in the acid, the acid that is dissolved with the nickel monomer is coated on the silica counterdie 12 of amorphous silicon film.In addition, the roughly process of manufacture craft is same as shown in Figure 1.

In the present embodiment, use the nitric acid of 0.1mol/1 as acid.It is 50ppm that nickel by powder is dissolved in the concentration that makes nickel in this nitric acid, uses as solution with this.After this technical process with

The situation of embodiment 1 is identical.

Embodiment 4

Present embodiment is represented, uses the crystal silicon film of the present invention's method making, makes the embodiment of the TFT of each pixel portion of liquid crystal indicator of being located at active array type.In addition, the range of application of TFT not only has liquid crystal indicator, in general, certainly is used for thin film integrated circuit.

Fig. 2 represents present embodiment manufacture craft process roughly.At first, on glass substrate, form the thick silica counterdie (not shown) of 2000 .The effect of this silicon oxide film is the diffusion of impurities that prevents from glass substrate, when introducing catalytic elements, has the effect that improves wetability.

Then, coating is dissolved with the acetate solution of 100ppm nickel, keeps 5 minutes, dries with spin coater.After this, in blanket of nitrogen, carry out prebake.

Introduce the technical process of nickel, can be undertaken by the method shown in embodiment 2 or the embodiment 3.

Then, form the amorphous silicon film of thick 1000 ,, carry out crystallization 550 ℃ of heat treated 4 hours by embodiment 1 identical method.Step process can obtain the crystalline state silicon fiml thus.

Secondly, to the silicon fiml needle drawing of crystallization, form island areas 104.This island areas 104 constitutes the active layer of TFT.Then, form 200～1500 , get the silicon oxide film 105 of 1000 in this example.This silicon oxide film also plays the effect as gate insulating film.

Must be careful for making above-mentioned silicon oxide film,, make raw material here with TEOS (tetrem oxosilane), with oxygen, be 150～600 ℃ at substrate temperature.Be preferably 300～450 ℃ by the RF plasma CVD method, decompose deposition.The pressure ratio of TEOS and oxygen is 1: 1～1: 3, and total pressure is that 0.05～0.5Torr, RF power are 100～250W.It perhaps is raw material with TEOS.With ozone, by decompression CVD or atmospheric pressure cvd method, be 350～600 ℃ at substrate temperature, be preferably under 400～550 conditions and form.After the film forming, in oxygen or ozone atmosphere, annealed 30～60 minutes at 400～600 ℃.

Under this state, with KrF excimer laser (wavelength: 248nm, pulsewidth: 20ns) or the strong illumination that is equal to it, can promote the crystallization of silicon area 104.Particularly, use ultrared RTA (rapid thermal annealing), glass substrate is not heated, and can only select heating silicon fiml itself, and can reduce the interface energy level that is positioned at silicon and silicon oxide film interface, thereby be favourable to the making of insulated-gate type field effect semiconductor device.

After this, form the aluminium film of thick 2000 ～1 μ m, with the needle drawing of aluminium film, form gate electrode 106 by the electron beam evaporation plating method.The scandium (Sc) that mixes 0.15～0.2wt% in aluminium is for well.Secondly, making substrate immerse pH is in about 7 1～3% tartaric ethylene glycol solutions, makes negative electrode with platinum, and aluminum gate electrode is made anode, carries out anodic oxidation.In anodic oxidation, make voltage rise to 220V with constant current at first, keep this state to finish after 1 hour.In the present embodiment, under the current constant state, the voltage climbing speed divides with 2～5V/ is advisable.So, form for example anodic oxide 109 of 2000 of thick 1500～3500 .(Fig. 2 B).

After this, by ion doping method (also claiming the plasma doping method), make mask with the gate electrode position and impurity (phosphorus) is injected in the island silicon fiml of TFT with self-aligned manner.With hydrogen phosphide (PH ₃) make impurity gas.Dopant dose 1～4 * 10 ¹⁵/ cm ²

And then shown in Fig. 2 C, irradiation KrF excimer laser (wavelength 248mm, pulsewidth 20ns) improves owing to introduce above-mentioned impurity making the degenerate crystallinity at position of crystallinity.Laser energy density is 150～400mJ/cm ², be preferably 200～250mJ/cm ²This has just formed N type impurity (phosphorus) district 108,109.The sheet resistance in this district is 200～800 Ω/.

In this technical process, irradiating laser can replace RTA (rapid thermal annealing), RTP (rapid thermal treatment), promptly uses photoflash lamp, at short notice, makes temperature rise to 1000～1200 ℃ (silicon monitors the sheet temperature), heated sample.

After this, make raw material with TEOS, with oxygen by plasma CVD method, or with ozone by decompression CVD or atmospheric pressure cvd method, the silicon oxide film that forms thick 3000 is as whole layer insulation thing 110.Substrate temperature remains on 250～450 ℃ for example at 350 ℃.After the film forming,, silicon oxide film is carried out mechanical lapping for obtaining smooth surface.Afterwards,, this is carried out needle drawing, form pixel electrode 111 (Fig. 2 D) by sputtering method deposition ITO film.

Then, insulant 110 between corrosion layer, shown in Fig. 1 (E), form TFT source, drain region contact hole, form chromium or titanium nitride wiring 112,113, wiring 113 is connected with pixel electrode 111.

Introducing the crystalline state silicon fiml of nickel through plasma treatment, because of comparing with silicon oxide film, be low to the selectivity of buffered hydrofluoric acid, thereby in the formation technical process of above-mentioned contact hole, the part that often is corroded is many.

But, as described in present embodiment, introduce under the situation of nickel the low concentration aqueous solution who uses 10ppm, because of hydrofluoric acid resistance is good, then can stably form above-mentioned contact hole, and reproducibility might as well.

At last, in 300～400 ℃ hydrogen, annealed 1-2 hour, finish the hydrogenation of silicon.So just finished TFT.And it is rectangular that each TFT that makes simultaneously is arranged in, and finishes active array type LCD.This TFT has source, drain region 108,109 and channel formation region 114.Other 115 constitute electricity NI knot.

Adopt under the situation of present embodiment structure, the nickel concentration that exists in the active layer is 2 * 10 ¹⁸Cm ³About or lower, think 1 * 10 ¹⁶At/cm ³～3 * 10 ¹⁸At/cm ³

Embodiment 5

Fig. 3 represents the sectional drawing of present embodiment manufacture craft.At first, on substrate (Corning 7059) 501, form the silica counterdie 502 of thick 2000 with sputtering method.Before or after counterdie forms, make substrate after being higher than the warm annealing temperature of distortion, slowly be cooled to deformation temperature when following with 0.1～1.0 ℃/minute speed, can reduce the contraction of substrate in the technology (comprising thermal oxidation technology of the present invention and subsequent thermal anneal process) of following the temperature rising thereafter, make the mask registering easy.When using Corning 7059 substrates, after 620～660 ℃ of annealing 1～4 hour, with 0.03～1.0 ℃/minute, preferably with 0.1～0.3 ℃ of/minute slowly cooling, when temperature drops to 400～500 ℃, from stove, take out.

Secondly, with the method described in the embodiment 1, make amorphous silicon film carry out crystallization.That is, the nickeliferous solution of coating makes the surface of nickel attached to amorphous silicon film 502 on silica counterdie 502.

Then,, form thick 500～1500 , for example the intrinsic of 1000 (I type) amorphous silicon film by plasma CVD method.Then annealed 48 hours, carry out crystallization, the silicon fiml needle drawing is formed the island silicon fiml (active layer of TFT) 503 (Fig. 3 A) that 10 μ m * 10 μ m～1000 μ m * 1000 μ m are square 600 ℃ blanket of nitrogen (under the atmospheric pressure).

After this, to make 500～750 ℃ of representative values under 1 atmospheric pressure of 70～90% water vapour be 600 ℃ oxidizing atmosphere containing, under the condition of hydrogen-oxygen ratio=1.5-1.9, carry out pyrolytic reaction, make the silicon fiml surface oxidation, form thick 500～1500 , for example the oxide-film 504 of 1000 .Should be noted that because through peroxidating, original silicon fiml, reduce more than 50 on its surface, its result, the heavy dirt of this silicon fiml uppermost surface can not be expanded to the silicon/oxidative silicon interface.The silicon/oxidative silicon interface that in other words, can obtain to clean.Because of the thickness of silicon oxide film is the thick twice of oxidized (preceding) silicon fiml, make the thick silicon fiml oxidation of 1000 , obtain under the situation of the thick silica of 1000 , the thickness of remaining silicon fiml is exactly 500 .

In general, silicon oxide film (gate insulating film) and active layer are thin more, and mobility is high more.Can obtain the good characteristic that cut-off current is reduced.So,, always just have characteristic and technologic contradiction about the thickness of active layer.The present invention has solved this contradiction first,, before crystallization, forms thicker amorphous silicon film earlier, to obtain good crystalline state silicon fiml that is.Subsequently, by making the silicon fiml oxidation, the attenuate silicon fiml is with thickness, to improve the characteristic of TFT.Have, in thermal oxidation process, has reduced in the complex centre that has in the active layer that makes the amorphous component that there is the complex centre easily, a knot grain boundary oxidation, makes gained again.Thereby improved the yield of product.

After forming silicon oxide film 504, make substrate 2 hours (Fig. 3 B) that in the atmosphere of 600 ℃ of (1 atmospheric pressure 100%) nitrous oxides, anneal by oxidation.

Then, by decompression CVD method, form thick 3000～8000 , for example the polysilicon of 6000 (containing 0.01～0.2% phosphorus).Then, to the silicon fiml needle drawing, form gate electrode 505.Make mask with gate electrode again,,, make N type impurity (being phosphorus herein) add active layer district, (formation source, leakage and channel region) to by ion doping method (also claiming the plasma doping method) with Alignment Method.With hydrogen phosphide (PH ₃) make impurity gas, accelerating voltage is 60～90KV, for example 80KV.Dopant dose is 1 * 10 ¹⁵～8 * 10 ¹⁵/ cm ²For example 5 * 10 ¹⁵/ cm ²Its result forms N type impurity range 506 and 507.

After this, anneal with laser radiation.Used laser is KrF excimer laser (wavelength 248nm, pulsewidth 20nsec), also can with other laser.The illuminate condition of laser, energy density are 200～400mJ/cm ², 250mJ/cm for example ², every shines for example 2 times 2-10 time.In the irradiating laser process, substrate is heated to 200～450 ℃, but reinforced effects (Fig. 3 C).

In addition, this step process also can with the near infrared lamp photo-annealing.Compare with amorphous silicon, the easier crystallized silicon of infrared ray absorbs, and can carry out and can effectively anneal in the same manner with the thermal annealing more than 1000 ℃.Otherwise, because of near infrared ray is difficult to be absorbed (though glass substrate can absorb far infrared by glass substrate, but visible light, near infrared ray (wavelength 0.5～4 μ m) are difficult to absorb), can not make glass substrate be heated to high temperature, short because of the processing time again, can be described as the technical process that is suitable for having glass substrate contraction problem most.

Then, form the silicon oxide film 508 of thick 6000 as the layer insulation thing by plasma CVD method.Also available polyimides is made this layer insulation thing.Form contact hole again, with metal material, for example the multilayer film of titanium nitride and aluminium forms electrode/wiring 509,510 of TFT.At last in 1 atmospheric nitrogen atmosphere 350 ℃ annealing 30 minutes.Finish TFT (Fig. 3 D).

The mobility of the TFT that is obtained by said method is 110～150cm ²/ Vs, the S value is 0.2～0.5V/ position.Use identical method, under the situation of mixing source, drain region making P ditch TFT with boron, mobility is 90～120cm ²/ Vs, the S value is 0.4～0.6V/ position, compares with the situation of using known PVD method or CVD method to form gate insulating film, and mobility can improve more than 20%, and the S value can descend more than 20%.

In addition, from the reliability aspect and opinion, the TFT that makes with present embodiment demonstrates the good result not second to the TFT that makes with 1000 ℃ of high-temperature thermal oxidation methods.

Use and introduce the crystalline state silicon fiml of catalyst elements, make semiconductor device, can boost productivity, also the good device of acquired character at low temperature short time crystallization.

Claims (22)

1. A utilization contain crystalline state silicon fiml in that the semiconductor device that constitutes the source region on the substrate of insulating surface is arranged, it is characterized in that,

   Aforesaid active area is to promote the catalyst elements of amorphous silicon film crystallization to be dissolved in the solution by making, keep below this amorphous silicon film, contacting, implement heat treated and form, wherein said catalyst elements is from Ni, Pd, Pt, Cu, Ag, Au, In, Sn, P, As, Sb, Fe, H ₂One or more elements of selecting among O, Co, Ru, Os, the Ir.
2. 2. the semiconductor device of claim 1 is characterized in that, is thin-film transistor, diode or photoelectric sensor at the semiconductor device of the formation of active area.
3. 3. the semiconductor device of claim 1 is characterized in that, the concentration of the catalyst elements in the aforementioned active layer district is 1 * 10 ¹⁶At/cm ³～1 * 10 ¹⁹At/cm ³
4. 4. the semiconductor device of claim 1 is characterized in that, active area has PI, a PN, NI knot at least.
5. 5. methods of making semiconductor devices, it is characterized in that, the compound that makes the catalyst elements monomer that promotes the amorphous silicon film crystallization or contain aforementioned catalyst elements keeps contacting below this amorphous silicon film, make contained aforementioned catalyst elements monomer or contain under the compound and aforesaid amorphous silicon film state of contact of aforementioned catalyst elements, implement heat treatment, make aforementioned amorphous silicon film crystallization, wherein said catalyst elements is from Ni, Pd, Pt, Cu, Ag, Au, In, Sn, P, As, Sb, Fe, H ₂One or more elements of selecting among O, Co, Ru, Os, the Ir.
6. 6. methods of making semiconductor devices comprises:

   The substrate surface coating that insulating surface is arranged make the catalyst elements dissolving that promotes the amorphous silicon film crystallization or the processing step of the solution that disperses and,

   On aforementioned substrate, form the processing step of amorphous silicon film, and

   To aforementioned amorphous silicon film heat treated, make the processing step of its crystallization,

   Wherein said catalyst elements is from Ni, Pd, Pt, Cu, Ag, Au, In, Sn, P, As, Sb, Fe, H ₂One or more elements of selecting among O, Co, Ru, Os, the Ir.
7. 7. methods of making semiconductor devices comprises:

   Coating makes compound dissolving that contains the catalytic elements that promotes the amorphous silicon film crystallization or the processing step that is dispersed in the solution in the polar solvent on the substrate of insulating surface is arranged;

   On aforementioned substrate, form the processing step of amorphous silicon film; And

   By heat treated to aforesaid amorphous silicon film, make the processing step of its crystallization,

   Wherein said catalyst elements is from Ni, Pd, Pt, Cu, Ag, Au, In, Sn, P, As, Sb, Fe, H ₂One or more elements of selecting among O, Co, Ru, Os, the Ir.
8. 8. the methods of making semiconductor devices of claim 7 is characterized in that, use from water, alcohol, acid, ammoniacal liquor, select one or more as polar solvent.
9. 9. the methods of making semiconductor devices of claim 8 is characterized in that, makes catalyst elements with nickel, and this nickel is to use with compound form.
10. 10. the methods of making semiconductor devices of claim 9 is used select at least a as nickel compound from nickelous bromide, nickel acetate, nickel oxalate, nickelous carbonate, nickel chloride, nickel iodide, nickel nitrate, nickelous sulfate, nickel formate, nickel acetylacetonate, 4-cyclohexyl butyric acid nickel, nickel oxide, nickel hydroxide.
11. 11. a methods of making semiconductor devices comprises:

    Having on the substrate of insulating surface, coating makes the compound that contains the catalytic elements that promotes the amorphous silicon film crystallization be dissolved or dispersed in the step of the solution in the non-polar solven;

    On aforementioned substrate, form the processing step of amorphous silicon film; And

    By heat treated to aforesaid amorphous silicon film, make the processing step of its crystallization,

    Wherein said catalyst elements is from Ni, Pd, Pt, Cu, Ag, Au, In, Sn, P, As, Sb, Fe, H ₂One or more elements of selecting among O, Co, Ru, Os, the Ir.
12. 12. the methods of making semiconductor devices of claim 11 is characterized in that, uses from benzene,toluene,xylene, carbon tetrachloride, chloroform, reaches select the ether a kind of as non-polar solven.
13. 13. the methods of making semiconductor devices of claim 11 is characterized in that, as catalyst elements, this nickel is to use with the form of nickel compound with nickel.
14. 14. the methods of making semiconductor devices of claim 13 is characterized in that, uses from nickel acetylacetonate, 4-cyclohexyl butyric acid nickel, nickel oxide, nickel hydroxide, reaches select the 2 ethyl hexanoic acid nickel at least a as catalyst elements.
15. 15. a methods of making semiconductor devices comprises:

    Having on the substrate of insulating surface, be mixed with the processing step of surfactant solution in the catalyst elements monomer solution of coating dissolving or dispersion promotion amorphous silicon film crystallization;

    On aforementioned substrate, form the processing step of amorphous silicon film; And

    By heat treated to amorphous silicon film, make the processing step of its crystallization,

    Wherein said catalyst elements is from Ni, Pd, Pt, Cu, Ag, Au, In, Sn, P, As, Sb, Fe, H ₂One or more elements of selecting among O, Co, Ru, Os, the Ir.
16. 16. a methods of making semiconductor devices comprises:

    The processing step that the material that contains the catalyst elements that promotes the semiconductor film crystallization is contacted with siliceous semiconductor film;

    By to the described heat treated that has the semiconductor film that contains the catalyst elements material, make the processing step of its crystallization;

    After above-mentioned heat treated, use infrared ray that described semiconductor film is carried out short annealing heat treatment;

    Wherein said catalyst elements is from Ni, Pd, Pt, Cu, Ag, Au, In, Sn, P, As, Sb, Fe, H ₂One or more elements of selecting among O, Co, Ru, Os, the Ir.
17. 17. a methods of making semiconductor devices comprises:

    The processing step that applies the solution that makes the catalytic elements that contains promotion amorphous silicon film crystallization on the substrate of insulating surface is being arranged;

    Then, on the insulating surface of described catalyst elements, form one deck amorphous silicon film;

    Described amorphous silicon film is heat-treated, use infrared ray that described semiconductor film is carried out short annealing heat treatment then;

    Wherein said catalyst elements is from Ni, Pd, Pt, Cu, Ag, Au, In, Sn, P, As, Sb, Fe, H ₂One or more elements of selecting among O, Co, Ru, Os, the Ir.
18. 18. a methods of making semiconductor devices comprises:

    Coating makes compound dissolving that contains the catalytic elements that promotes the amorphous silicon film crystallization or the processing step that is dispersed in the solution in the polar solvent on the substrate of insulating surface is arranged;

    Then, on the insulating surface of described catalyst elements, form one deck amorphous silicon film;

    Described amorphous silicon film is heat-treated, use infrared ray that described semiconductor film is carried out short annealing heat treatment then;

    Wherein said catalyst elements is from Ni, Pd, Pt, Cu, Ag, Au, In, Sn, P, As, Sb, Fe, H ₂One or more elements of selecting among O, Co, Ru, Os, the Ir.
19. 19. a methods of making semiconductor devices comprises:

    The processing step that the material that contains the catalyst elements that promotes the semiconductor film crystallization is contacted with siliceous semiconductor film;

    By to the described heat treated that has the semiconductor film that contains the catalyst elements material, make the processing step of its crystallization;

    After crystallization step, described semiconductor film is made the semiconductor island pattern;

    On semiconductor island, form grid;

    Use at least one described grid as mask, introduce foreign ion with self-aligned manner, to provide its a kind of types of conductors to the subregion of described semiconductor island; And

    Use short annealing heat treatment, make at least and anneal in the semiconductor island subregion;

    Wherein said catalyst elements is from Ni, Pd, Pt, Cu, Ag, Au, In, Sn, P, As, Sb, Fe, H ₂One or more elements of selecting among O, Co, Ru, Os, the Ir.
20. 20. the method for claim 19, wherein said short annealing heat treatment is to use near infrared ray to carry out.
21. 21. it is that the near infrared ray of 0.5-4 μ m carries out that the method for claim 19, wherein said short annealing heat treatment are to use wavelength.
22. 22. the method for claim 21, wherein said semiconductor film forms on glass substrate, and glass substrate is littler to the absorption coefficient of light than described semiconductor island to the absorption coefficient of light.

Images