Selective epitaxial growth method

[Detailed Description of the Invention]

b) Field of the Invention The present invention is made into the alternative epitaxial growth method which grows up a single crystal Si film alternatively only on the portion which 84 substrate faces without 5I02 film have exposed on the single crystal and Si substrate which formed 5IOz film alternatively in between. a mouth -- PRIOR ART The thing in which the single crystal Si layer was formed on insulation R (the substrate of an insulator is also included) is S OI (Silicon on In5ulat.). r) It is called structure, element isolation can be easily performed in a narrow field, and it is known as what can be integrated highly and accelerated. Compared with A and the integrated circuit (fc) in which an element is produced on the conventional Si substrate, research and development are briskly done from the ability of improvement in the characteristic to be aimed at. As a thing which makes a single crystal Si film form on a A R layer, there is the said phase growing-epitaxially method and it is this, On single crystal 81 board, it is S! A part of substrate side is exposed as seed, an insulating film is formed, and they are amorphous S and I on seed and an insulating film. A film (following a-94 is called) is deposited, by Annealing(ing) at the low temperature about 600 degreeC, the said phase growth is carried out to a transverse direction, and an a-8i film is U.S.-crystallized. however -- since Thoroughness crystallization of an a-3t film progresses with the priority to the transverse direction of the <100>directions in this phase growth of the In the phase epitaxial growth which needs growth of the lengthwise direction from seed to [ upper ] before growth of a transverse direction, a-5ill[on seed cannot be thickened and, for this reason, the not much large level difference of seed and the insulating film surface cannot be taken. however, the insulating film in which the level difference of 5 seeds and the insulating film surface size-comes, and goes when an a-3i film is thin -- it is thick Since the internal stress in a stepped part becomes large even if a stage piece does not arise in the portion of the boundary of an insulating film and seed on the a-5i film to deposit or a stage piece does not arise, even if the phase growth of a transverse direction hardly occurs or occurs, it becomes slight [ transverse direction growth distance ]. For this reason, the level difference of seed and the insulating film surface is small as much as possible, namely, needs to make an insulating film thin, and is usually formed below in 1000A. However, when it constitutes the three-dimensional circuit element which laminated Sol structure and the protection for device structure, wiring, and stabilization of an electrical property is taken into consideration since a device will be formed under an insulating membrane layer, the film thickness more than IAIa is needed as an insulating film. That -- a trowel, For example, '5ELECTIVE EPITAXIAL GROWTtlOF 5ILICON BY CVD AND ITS Ding HERMODYNAMICC0N5IDERATIONJ (PROCEEDINGS OF THE TENTHINTERNATIONAL C0NFERENCE ON CHEMICAL VAPORDEPO5ITION 1987. Proceedin@ As it is in Vol, 87-8. PP, and 379-388>, it is 5iHxC12-HCj to up to the single crystal si board in which 5if2 film punctured alternatively was formed! The decrease ffCVD method of -H5(') normal pressure CVD Aruuha, Sl board side top exposed with the substrate temperature of case of normal pressure 950degreeC thru/or 1050degreeC, case of decompression 850degreeC, or 950 degreeC -- a single crystal Si film -- Formation -- long To [!! ] -- Selection epitaxial growth (Selective Epitaxial Gr.) wth : law is considered 5 EG below. Deposition of the single crystal Si film to the exposed substrate according [ the SEG method using this chlorine-based gas ] to thermal decomposition of Ran system gas side top, and the multi-crystal Si film to a SfOglI top, Etching by HCffi to Si film these-formed is caused simultaneously, and deposition of Si film to 5iovX top is lost using multi-crystal Sil!l having a Etbung speed larger than a single crystal Si film. C) By Object of the Invention, however the SEG method using above-mentioned chlorine-based gas, CI considered to be etchant! Etching is made because radical attacks and cuts 5 i-st pound or 5i-0 pound, and it is this etching, While depositing, many defects occur the crystal Si film surface and near the multi-crystal Sl film surface, When making an a-8i film deposit further on Si film formed by this SEG method and carrying out phase epitaxial growth of this a-81 film, CP atom which remains in an a-5i film will mix, and crystallization will be checked. And the growth distance of a transverse direction becomes short and the substrate of the Sol structure of a large area will be obtained as a result. The life of a CVD device (especially decompression CVD device) will also become short again. the present invention -- Such -- it was accomplished in view of the point [ like ], and the SEG method for growing a single crystal Si film epitaxially only on the exposed single crystal St board is provided, without using gaseous chlorine. 2) Means for solving problem The present invention forms an insulating film on a single crystal Si pedestal, and it forms in the above-mentioned insulating film the puncturing part in which the above-mentioned single crystal Si pedestal surface is exposed, the decompression vapor phase epitaxy according a single crystal Si film to the thermal decomposition of SiH4 only to the above-mentioned single crystal Si pedestal portion exposed in the puncturing part formed in the insulating film -- alternative -- epitaxial Formation -- it is a long To alternative epitaxial growth method The point of substrate temperature 890degreeC at the time of taking substrate temperature along a horizontal axis and taking the SiH* partial pressure of gas along a vertical axis, and 5ii4 partial-pressure-of-gas OmTorr, The line which passes along two of the points of substrate temperature 950degreeC and SiHm partial-pressure-of-gas 20mTorr is made into a boundary line, and decompression vapor phase epitaxy by the thermal decomposition of SiH4 is performed from the boundary line with the substrate temperature and the 51g4 partial pressure of gas of the range of a side with a high temperature. Ho) OPERATION Since the 5ho2 surface which is an insulating film has few dangling bonds of St from the first compared with the single crystal 81 surface, There is few Kyn Kusa Ito which the surface adsorption kind (Si) in a reaction combines, if pedestal temperature is made high enough, surface migration of a surface adsorption kind will become intense, and adsorption to Kyn Kusa Ito of a surface adsorption kind will become is hard to be carried out there where the core of crystal Si does not occur easily on the 5i film 2 surface. 5 (a possibility of being exhausted by making H4 partial pressure of gas into a sufficiently high degree of vacuum before the Surface absorption !1 sort in surface migration sticks to a king site becomes high.) By Therefore(ing) and making pedestal temperature and the SiH4 partial pressure of gas into within the limits like Above, Si film does not grow on an insulating film, but a single crystal Si film grows epitaxially only on the single crystal St pedestal exposed from the puncturing part. What) EXAMPLE Single crystal S formed on the substrate although Drawings 1 A thru/or G used single crystal 51 substrate as a single crystal Si pedestal in 0 this example which shows the outline flowchart of present invention 1 example (a film may be used.) (1) is single crystal 81 substrate as single crystal 81 pedestal which makes (100) a field the principal surface, A and photograph ring Lafi art which is the publicly known art about these 5102 films (2) which form about four film thickness [ IN ] 5ift film (2) in that surface by change between heat as an insulating film (Drawing 1 A), The puncturing part (2a) in which the Si-substrate surface as seed is exposed is formed alternatively (Drawing 1 B). Next, Temperature rising heating of the substrate which has this 5I02 film (2) by which pattern formation was carried out is carried out to 940degreeC with an infrared lamp in the vacuum below I X 10-@taTorr, When [ this ] introducing Ar gas by 150 cc of flows / ++in, using Ar pressure 65mTorr, performing Ar sputtering and cleaning a substrate face for 5 minutes, after seting temperature constant (Drawing 1 C), For example, RF frequency is 13.56MH21 output 50W, and it impresses the direct-current bias of -toov to the substrate. When surface cleaning finished, have maintained substrate temperature at 940 degreeC. Supply of Ar gas is stopped, RF and direct-current bias are cut, and it is flow 4 sccm pressure (it is single crystal S (a film (3) is grown epitaxially alternatively.) only on Sl substrate face (seed section (1a)) which was supplied by partial pressure >13mTorr and has been exposed from the puncturing part (28)) about 5iHn gas. This single crystal Si film (3) is grown up to the same film thickness as 5i02 film (2) (Drawing 1 D). Installing in In harmony and the reaction interior of a room of the vapor phase growth system which performed alternative epitaxial growth, supply of SiH4 gas is stopped and it is in the vacuum not more than I X 101mTorr, After reducing substrate temperature to 550degreeC, Ar gas is again supplied to Flow t500 cc/m1ll and A r partial pressure 200mTorr, coming out of 13.56-MHz RF and impressing by Cuffe 0W -- a substrate -- 1 -- the direct-current bias of 60V is hung and the substrate face by Ar sputtering is cleaned for 10 minutes (Drawing 1 E). And when surface cleaning finishes, it is in the state which maintained substrate temperature at 550 degreeC, since supply of Ar gas is stopped and RF and direct-current bias are cut -- the reaction interior of a room -- 5fH4 gas -- flow 200sccm and partial pressure 6 -- < -- or -- supplying by 7Torr -- a substrate face top -- a 1-8i film (4) -- 6000 persons' (200 growth rate 7sin) thickness -- deposition Avoid (Drawing 1 F). Then, if the SiHa gas which introduces Ar gas into the reaction interior of a room, and remains is exhausted, vacuum suction will be performed and substrate temperature will be lowered to room temperature. And using a Annealing device, the annealing treatment for 12 hours in the temperature of 600 degreeC performs phase epitaxial growth of a 5i-8i film (4) in atmospheric pressure N Atomi atmosphere, and it is the a-5i IN (To which obtains the single crystal Si film (4') which made 4> single-crystal-ize the 1st mG). Now, it is although SEG is performed in the process shown in 1st planning, If the deposition Can fix single crystal Si film (3) surface has many defects in a-81 film (4), A time delay after beginning Annealing of a-51 film until the phase growth happens becomes long, and the epitaxial growth distance of the transverse direction of a *-9i film becomes short, and they are many crystals S on 5ift film (2) (when a core occurs). Since the many crystal nuclei which prevent epitaxial growth occur early, the epitaxial growth distance of the transverse direction of an a-8i film becomes short too. the [ therefore, ] -- it is necessary to perform SEG satisfactorily at the process planned one Drawing 2 is a figure showing substrate temperature when not occurring with the time of SEG occurring, and the relation of the SiH4 partial pressure of gas. As for a white circle, RLvJ Crystal Si Model grows epitaxially only on S+ board, When Si film does not accumulate on 5iOz film (that is,> in which SEG occurs is shown, an east crystal Si film grows epitaxially on 51 boards, and the black dot shows S (To, i.e., SEG, does not occur when a film accumulates) also on 5iOz film.) Pedestal temperature is taken along a horizontal axis, the S i Ha partial pressure of gas is taken on t# axis, and they are substrate temperature 890degreeC and SiH4 partial pressure of gas O1 so that clearly from Drawing 2! Point a of Torr The line which passes along two substrate temperature 950degreeC and SiH4 partial-pressure-of-gas 20mTorr burning is made into a boundary line, and SEG is realized only when setting up and carrying out decompression vapor phase epitaxy to the substrate temperature and the SiH4 partial pressure of gas of the range of a side with a high temperature from this boundary line. This is surface migration of a surface adsorption kind becoming intense, and adsorption to Kyn Coosa Ito of a surface adsorption kind becoming difficult to go out, and making the SiH4 partial pressure of gas into a sufficiently high degree of vacuum, when pedestal temperature is made high enough, A possibility of being exhausted before the surface adsorption kind under surface migration sticks to a king site becomes high. It is Sh by Therefore(ing) and setting pedestal temperature and the SiH< partial pressure of gas as the range shown in Drawing 2 with a slash. Deposition of Si film of only single crystal Si-substrate-To is carried out, without depositing Si film on 2 films, namely, SEG is performed. A) EFFECT OF THE INVENTION The present invention can perform SEG by controlling the substrate temperature 5iHh partial pressure of gas, without using gaseous chlorine so that clearly from the above explanation. Therefore, an opportunity to control that a defect occurs on the single crystal Si film which serves as seed for carrying out phase epitaxial growth, and for impurities mix into an a-5i film can be reduced. As a result, when carrying out the said phase epitaxial growth of the a-5l. film, it becomes possible to be able to develop the growth distance to a transverse direction and to provide the substrate of the SOI structure of :large area. It is contribution Be trimmed for lengthening the life of growth devices, such as a decompression CVD device, since gaseous chlorine is not used.

[Brief Description of the Drawings]

It is Show 1 figure about conditions for Drawings 1 A thru/or G to realize the process explanatory view of present invention 1 example, and for Drawing 2 realize SEG. (1) ... a single crystal Si substrate and (la) ... seed and (2) ... 5i02 film (insulating film) and ... (2a) -- a puncturing part (3> ... eye single crystal S L (4) ... an a-Sl film (4') ... single crystal S (film.)), Drawing 1