JPH0393220A - Formation of crystalline thin film and manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To prevent crystalline defects due to seed crystals and to acquire a high quality Si crystalline film by forming a crystalline film on an insulating film and by further forming a crystalline film thereon having a lower crystalline defect density than the crystalline film and the same crystal orientation as that of the crystalline film. CONSTITUTION:A pattern of an SiO2 film 2 is formed on a single crystalline Si substrate 1 and an amorphous Si film 3 is formed on the substrate through electron beam heating evaporation method. Then, heat treatment is applied in super high vacuum to produce solid epitaxial growth. The amorphous Si film 3 is single- crystallized on the film 2 ranging over a width of about 6mum from an end of the film 2. An amorphous Si film on the film 2 which is 6mum or more apart from an end of the film 2 becomes a polycrystalline Si 9. Similarly, electron beam heating evaporation is carried out in super high vacuum; the amorphous Si film 3 is formed on an Si film 10 which is deposited previously; heat treatment is carried out; and solid epitaxial growth is caused which proceeds in a longitudinal direction using an Si film 7 as seed crystals, which is crystallized in a preceding process. Thereby, a high quality Si crystal which is free from crystal defects can be obtained on an SiO2 film.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a silicon-on-insulator (S01) used as a substrate for a semiconductor device (single element, integrated circuit).
(conductfor-on-1nsulafor) relates to a method of forming a crystal and a method of manufacturing a semiconductor device using a Sol crystal. [Prior Art] An SOI structure in which a single-crystal Si film is formed on an insulator is expected to be a basic structure for future LSIs and high-voltage devices, and is being studied. Among several SOI formation techniques, the solid-phase epitaxial growth method has excellent uniformity and reproducibility, and has a high potential to eventually become mainstream. This process will be briefly explained using Figure 2. An insulating film 2 with holes partially formed is formed on a single-crystalline Si substrate 1, and ultra-high vacuum evaporation method or chemical vapor deposition method (C
An amorphous Si film 3 is formed using the VD method. If this is heat treated at a low temperature (about 600℃) using an electric furnace, the base &
Single crystallization (in-phase epitaxial growth 4) of amorphous Si3 occurs from the point in contact with sil. Since the growth extends to the top of the insulating film 2, a Sol structure is obtained. During lengthening, some long ends are formed with special crystal planes (facets 11) due to the influence of the insulation layer 2. This facet 11 influences the speed of a certain length and the quality of the delivery obtained. In solid phase epitaxial growth, (100) and (110)
Growth on the surface and a certain length on the (111) surface are good in that order. It is most preferable to lengthen it with a (100) facet. However, (100) facets do not occur on the insulating film, so as a next step, (1 1 0
}Crystals will grow with facets. Therefore, (100) in the direction of the substrate surface and <1 in the direction of the side of the insulating suction 2 opening.
0 0> is usually selected. A variation of this technique is shown in Figure 3. There is a technology that uses a two-layer film of amorphous [Si5] containing a high concentration of P (or impurities that are electrically active in single crystal Si, such as As and B) and amorphous Si6 that does not contain these impurities. ．． This is a method devised to expand the area of the in-phase long Sol region. The area of the solid phase long SQL is determined by the balance between the solid phase epitaxial growth rate and the polycrystallization time of amorphous Si3. That is, after a certain heat treatment time elapses, amorphous Si3, which has not yet been crystallized, becomes polycrystalline, and solid phase epitaxial growth stops. Therefore, the key to *P,As. About 3 dopants such as B
If it is mixed into amorphous Si at a concentration of However, the impurity concentration is too high to be used in LSI. Therefore, a two-layer film method was devised, which achieved fast growth in the high impurity concentration layer 5. For LSI applications, a non-doped layer 6 is used (see Figure 3). In this case as well, it grows with (1 1 0) facets. As a report related to this method, JP-A-60-245211
No. Publication, Institute of Electronics, Information and Communication Engineers Technical Research Report 81) M87-
163. Materials Research Society (Mat
arials I {esearch Society)
's Fall ●Meafin
g) Extended Abstracts Selected Topics in Electronic Materials pages 121 to 128 (l{extended
AbstractsSelected Topics
in l(electronic Materials,
PP. 121-128). SON is made using the conventional two-layer film method, and MO is added thereto.
The experimental results of our fabrication of SFIT are described below. on a single crystal Si substrate with plane orientation (0 0 1). The most commonly used LOGOS (Local Oxidation of Silicon)
Using the tion of Si method, the thickness of 500
An iO laziness pattern was formed. The sides of the pattern are [0 1
0] direction. After this sample was wet-cleaned, it was introduced into an ultra-high vacuum chamber with a back pressure of 10" Torr, where it was heat-treated at 900°C for 30 minutes to perform surface cleaning. The substrate temperature was raised to 100°C. Immediately, Si was deposited on the substrate by electron beam heating evaporation to form an amorphous Si film (thickness: 0.2 μm). B ionization doping was used in conjunction with boron (H) concentration of 3 x 10 ``cs-'' for 0.05 μm and 2 x 10'' for the next 0.05 to 0.2 μm. ．． Thereafter, heat treatment was performed at 450°C for 1 hour in the same ultra-high vacuum to densify the amorphous [Si]. This sample was taken out of the ultra-high vacuum chamber and heat-treated at 600°C in an electric furnace to obtain an SQL with a width of 5 to 8 μm along the pattern edge of the aS x Ox film that was subjected to solid phase epitaxial growth.
To examine the facets, separate the sample during growth and lightly etch it with a Vright etching solution (selective etching solution for crystal defects). converted into Si
The boundaries of Observation of the cross section revealed that the growth edge was made up of a single facet that spanned the low B concentration layer and the high B concentration layer, as shown in Figure 3 (Q). In other words, similar to the previous paper, lateral height was generated at both the upper and lower elbows at the same time. Also, by applying 45″ in the [0 1 0] direction on the sample surface,
Since the (110) cross section forms an angle of 55° with the surface of the substrate ((001)), it can be seen that the long end is more sensitive than the (111) facet. Thereafter, an n-channel MOSFIfT (source and drain regions formed by As doping) with a gate length of 1.2 μm was fabricated in the Sol region, and its electrical characteristics were evaluated. The field effect mobility of electrons in the channel is 230aj/v
-S, the results were comparable to those of MOSf/HT fabricated in the (1 1 1) facet growth region of a normal single-layer film. In addition, recently. By fabricating MOS transistors on SOI with a SiM thickness of less than 1,000 nm, it is possible to achieve significant performance improvements, such as improved drive capability, compared to those fabricated directly on conventional Si wafers. Reports are coming in. In these reports, electron beam annealing or laser beam annealing is used to prepare the sample.
A common method is to create an SQL with a normal thickness (0.3 pm to 1 μm) using an annealing method or an oxygen ion implantation method, and then reduce it to a thickness of 1,000 or more by polishing or dry etching. It is being done. I from the beginning
There is no example of a thin 501 made below OOOA. [The invention seeks to solve *M3 501 formation in which growth progresses horizontally on the insulating film 2 is different from normal solid-phase epitaxial growth (see Figure 4) in which growth progresses vertically over the entire wafer surface. Localized.
Therefore, the stress associated with crystallization is concentrated here, and crystal defects (dislocations) are likely to occur in the crystal. In other words, it is difficult to make perfect crystals. When considering the formation of a perfect crystal, there is another thing to consider: (100
) The problem is that it is not possible to make a certain length on the surface. Taking the electrical activation rate of an impurity (Ag) as an example of an index of crystallinity, it is 100% in a crystal grown on the {00} plane.
While a close value (95%) is obtained, (1 1 0)
In crystals grown on the (111) plane and (111) plane, only small values of about 84% and about 68% are obtained, respectively.Of course, here, the lower the activation rate, the worse the crystallinity. This data shows that (110) growth has much better crystallinity than (1 1 1) extrusion, but it is still not perfect. As expected, it is best to grow at (100). The purpose of the present invention is to realize solid-phase epitaxial growth on an insulating film that is non-localized and proceeds with (100} facets, and thereby to develop a technology for forming high-quality crystalline SQL with good uniformity and reproducibility. By the way, SOI (ultra-thin film SOI) with a Si thickness of 1000λ or less
The method used to form oI, that is, the method of scraping the film to achieve the desired thickness, is not practical as an LSI process because the control accuracy and uniformity of the film thickness within the wafer surface are poor. However, it would be better if SOI could be made from an ultra-thin film from the beginning, but there is currently no such technology. In the III-phase epitaxial growth method, when amorphous Si is thinned to 0.2 μm or less, the elongated pattern becomes (1 1 1) facet growth. Ideally, it cannot be applied to LSI unless it has (1 0 0) facets or at least (1 1 0) facets or length. Another object of the present invention is to provide a process technology that can form an ultra-thin film of Sol without cutting. [Means for Solving the Problems] In order to achieve the above two objects, in the present invention, a single crystal film 7 is once formed on the insulating film 2, and this is used as a seed crystal to generate vertical in-phase epitaxial Growth (see Figure 1)
．． If a device is fabricated on this SOI, the leakage current will be 1
It can be classified into a component flowing through the crystal kII7 formed in the second growth and a component flowing through the crystal layer 8 formed in the second growth. In order to reduce the former, electroactive impurities such as P, A s g B, or elements with high electronegativity such as F and C are introduced into the first layer 7. Since the first growth occurs on facets other than the (100) facet, the crystallinity cannot be said to be perfect. The second Kaicho process proceeds with the (100) facet, so high-quality crystals can be obtained. However, since the first crystal is used as a seed crystal, the probability of a defect occurring there is 21! ! It invades the first product. If a large number of elements are formed in S01, some of them will encounter this element. In order to prevent this defect from entering and obtain a perfect crystal, Ge, Sn
An element with a larger atomic radius than Si, such as Si, is introduced into the second layer 8. [Function] As shown in FIG. 1, the present invention forms Sol by vertical growth using the seed crystal layer 7 formed on the insulating film 2 as a seed. Because vertical growth occurs simultaneously over the entire surface of the wafer, the stress associated with crystallization is dispersed and crystal defects (dislocations) are less likely to occur. Further, vertical growth with the surface of the seed crystal 7 set to the (100) plane (that is, the substrate plane orientation is set to the (100)
) growth occurs. Growth on the (100) plane is a certain elongated mode that yields the highest quality crystals. Dispersion of stress. The two realizations of (100) modal growth allow the formation of extremely high quality Sol. By making devices using high-quality crystals, it is possible to obtain high-performance devices that operate quickly and have low leakage current. That is, a high-performance SOI device can be obtained with the present invention. However, in devices where the region involved in operation reaches the seed crystal layer '1, which is formed by lateral growth, the leakage current increases slightly by the amount of current flowing there. Particularly in the case of device applications where operation with small leakage current is desired, it is desirable to reduce the current in the seed crystal layer 7 by a certain amount. Therefore, P.As. electrically active impurities such as B,
or. Elements with high electronegativity such as F and C are introduced into the seed crystal layer 7. The introduction of electrically active impurities changes the electrostatic potential of the seed crystal layer 7 (it becomes higher when the leakage current carrier potential is positive, and lower when it is negative), and the leakage current carrier charge flows into it. The introduction of F, C, etc. achieves the inactivation of defects by coupling electrically active dangling bonds in crystal defects with these impurities, and reduces leakage current in the seed crystal layer 7. (generation of electron-hole pairs). It also suppresses the movement and growth of defects. Mixing atoms (Os, Sn, etc.) larger than the base material atom (Si) into the material is an atom rl! 1 distance IIl'! It means to increase (lattice, spacing) on average. A situation where a crystal has a crystal defect is a situation where the interatomic distance locally increases (at the crystal defect area). Therefore, if an impurity with a larger atomic radius is introduced onto the base crystal 7 that has crystal defects and the crystal is lengthened, the increase in the distance between atoms aggregated in the defects will increase the average and overall atomic distance in the Icho layer. This is converted into an increase in the distance between crystals and the crystal defects disappear. [Examples] Examples of the present invention will be described below. (Example 1) On a single crystal Si substrate 1 (see FIG. 1(a)) with a plane orientation of (100), two patterns of Sins films with a thickness of 1500 μm were deposited.
It was formed by the ocos method. After normal wet cleaning, 900'C. in an ultra-high vacuum (~10-@Pa). The substrate surface was cleaned by heat treatment for 30 minutes, and then a 3-thickness layer was immediately deposited on the substrate by electron beam heating evaporation.
000 amorphous Si film 3 was formed. continue. Heat treatment was performed at 600°C for 8 hours in an ultra-high vacuum. This heat treatment causes circumferential epitaxial growth, and on the SiOz film 2,
Sins1! Amorphous S over a width of about 6 μm from the I2 end
The i-film 3 became a single crystal (Fig. 1(b)). SiOztl
#2 Amorphous 9 on SiOa film 2 separated by 6 μm or more from the edge
1 S i wAha 8 knots M S i 9 Nift ivy.
Next, electron beam heating evaporation was performed in the same ultra-high vacuum, and as shown in FIG. 1(c), the previously deposited Si film 10 was
An amorphous Si film 3 with a thickness of 5,000 wafers was formed on top of the wafer. By heat-treating this at 600°C, vertically progressing solid-phase epitaxial growth occurred using the Si film 7 crystallized in the previous step as a seed crystal (Fig. 1(d)). As a result, a high-quality Si crystal without crystal defects was obtained on SiOzn% (first circle (e)). (Example 2) A Si Ox PIA2 pattern with a thickness of 1800 wafers was formed by the LOCOS method on a single crystal Si substrate 1 with the (100) orientation as shown in FIG. Apply resist to this,
The substrate surface was made flat and rough using a common flattening technique called etch-back using dry etching. As described in Example 1, this was subjected to normal wet cleaning and then heated cleaning in an ultra-vacuum to clean it. On top of this, a layer with a thickness of 300λ was deposited using an ultra-vacuum electron beam heating evaporation method.
An amorphous Si film 3 is formed (FIG. 5(a)). 600℃
By performing heat treatment for 10 hours, the amorphous Si film 3 was made into a single crystal by solid phase epitaxial growth (7) (FIG. 5(b)). Subsequently, electron beam heating evaporation was performed in a super-vacuum,
An amorphous Si film 3 with a thickness of 700λ was formed (Fig. 5(c)).
). Heat treatment (30 minutes) at 30° C. is performed again to cause solid phase epitaxial growth in the vertical direction using the Si film 7 crystallized in the previous step as a seed crystal (FIG. 5(d)). S
Completed single crystallization of i[3. As a result, a high quality ultra-thin [Si crystal with no crystal defects was obtained on a Si(la film)].
Fifth circle (e)). (Example 3) Single crystal Si substrate 1 with a curved orientation (100} such as 1111)
Loc the pattern of Sing film 2 with a thickness of 1500 people on top.
It was formed by the US method. After normal wet cleaning, the substrate surface is cleaned using heat treatment in an ultra-high vacuum. Amorphous Si [3] was deposited to a thickness of 2000 nm by electron beam heating evaporation. In addition, 40 keV・l. 75X10"aa""280
keV ・3.25XIO 5"cm-", 160
keV-9.5 The reason why multiple ion implantations are performed is to keep the p4 degree in the film constant.) In addition, for ion implantation,
The sample must be taken out of the ultra-high vacuum chamber, but if you take it out carelessly, oxygen and water molecules in the atmosphere may turn into amorphous S.
i @ 3 invades inside. These are factors that inhibit the solid-phase epitaxial growth, so in this example, S
Immediately after the i-evaporation, low temperature (450°C) is carried out in a super island vacuum.
This problem was solved by performing heat treatment (for 1 hour) to densify the amorphous Si film 3 (slowing down the diffusion of 0, HzO to a negligible level). This sample was heat-treated in an electric furnace at 600°C for 8 hours (Na
atmosphere) and amorphous Si in lateral solid-phase epitaxial
The film 3 was formed into a single crystal product (after this single crystal formation, heat treatment at 950° C. for 30 minutes may be performed for P ion implantation and P activation).

After cleaning the substrate surface again, a 7000λ thick amorphous [S
i3 was deposited. Next, heat treatment was performed at 600°C for 30 minutes, and the solid-phase epitaxial growth progressing in the vertical direction using solid single-crystal SiW47 as a seed crystal was shown in Figure 1(d).
The high quality Si crystal ISI8 was prepared as shown in the figure below.
Obtained on S membrane 2. In addition, instead of P, similar experiments were conducted with As and B, and the effectiveness of the present invention was also confirmed with As and B. (Example 4) Two patterns of SiOx films with a thickness of 1800λ were deposited by LOCO on a single crystal Si substrate l with a plane orientation (100) as shown in Fig. 1.
It was formed by the S method. After normal wet cleaning. Ar sputter etching in ultra-high vacuum and 800'C. The substrate surface was cleaned by heat treatment for 30 minutes. Immediately perform electron beam heating evaporation in an ultra-high vacuum to deposit a 2-thick layer on the substrate.
000 amorphous Si film 3 was formed. To this, 40
k e V-1.05X10"as-", 80kaV
-1.95X10"z-"160keV・5.7X10
Ion implanted P (phosphorus) under the conditions of ``(!1''d),
The P concentration in the film was set to 3×10"Oam-'. In this example, as in Example 3, a low-temperature heat treatment (450°C, 1 ffl for 1 hour) for densification was performed before taking the sample out into the atmosphere. After ion implantation, electric momme i
Lateral solid-phase epitaxial growth was performed by heat treatment at 600°C for 10 hours (in an N2# atmosphere) * P g A
! ! If an impurity such as yH that becomes a dopant for Si is present in a length of about IXIO"'(Jl-" or more), solid phase epitaxial growth is promoted, so in this example, a long lateral growth of about 20 μm can be obtained. After cleaning the substrate surface again, amorphous S with a thickness of 8000 nm was deposited using electron beam heating evaporation in an ultra-high vacuum.
i3 was deposited. Then, 600℃. Heat treatment was performed for 40 minutes, and solid phase epitaxial growth proceeding in the vertical direction using the solid single-crystalline Si film 7 as a seed crystal was performed in the 115th! I (
As shown in d), a high quality Si crystal film 8 is formed by Singing.
Obtained on membrane 2. It was also confirmed through experiments that the present invention is equally effective for P and H. (Example 5) On a single crystal Si substrate 1 with a plane orientation (100), two turns of a Sift film with a thickness of 1700λ were LOCized as shown in FIG.
It was formed by the OS method. The surface of this substrate was made flat using a common planarization technique. After cleaning the substrate surface, electron beam heating evaporation in an ultra-vacuum with ionization doping of P was performed to form an amorphous layer containing 3x10"3-a of P with a thickness of 200 mm on the substrate. A quality Si film 3 was formed (FIG. 5(a)). This was heat-treated at 600° C. for 10 hours, and the film 3 was made into a single crystal by solid phase epitaxial growth (FIG. 5(b)). Subsequently, electron beam heating evaporation was performed in an ultra-high vacuum.
An amorphous silicon film 3 with a thickness of 600 mm was formed (Fig. 5(c)
))． This was heat-treated again at 600°C (30 minutes), and as shown in Figure 5(d), the Si crystallized in the above step was
Using the film 7 as a seed crystal, in-phase epitaxial growth with a certain length in the vertical direction was caused, and the amorphous Si film 3 deposited for the second time was crystallized. This allows high-quality Si ultra-thin film crystal 8 to be
was obtained on the membrane (Fig. 5(a)). In addition, instead of P. Similar experiments were conducted with As and B,
We have confirmed that the present invention is effective for the customer. (Example 6) The same process as in Example 5 was carried out using PIA degree 3XlO”03-
J1, high-quality Si ultra-thin film crystal 8 was formed on Si021.
! Obtained on 112. Furthermore, a similar experiment was conducted using As and B instead of P, and a high quality Si ultra-thin film crystal 8 was similarly obtained on SiOxlM2. (Example 7) Two patterns of Sing films with a thickness of 1500 mm were deposited on a single crystal Si substrate 1 with a plane orientation of (100) by LOCOS as shown in Fig. 1.
Formed by law. After normal wet cleaning, the substrate surface was cleaned using heat treatment in an ultra-high vacuum. After that, the thickness of
,000 amorphous Si films 3 were deposited. This is heated to 600℃
After heat treatment for 7 hours, lateral solid-phase epitaxial growth occurred and single crystals were formed. F (fluorine) was introduced into this by ion implantation. In order to sufficiently distribute the fluorine into the defects in the solid phase epitaxial growth layer 7, heat treatment was performed at 900° C. for 30 minutes. The defects in the first layer of Silo were inactivated.After this, the substrate surface was cleaned, and then amorphous 'IYSi3 with a thickness of 7000 nm was deposited by electron beam heating evaporation in an ultra-high vacuum. By heat-treating this at 600°C for 30 minutes (in an ultra-high vacuum), vertical solid-phase epitaxial growth occurred as shown in Figure 1(d), resulting in single crystallization.
As a result, a high quality Si crystal film 8 was obtained on the Sift film 2. (Example 8) Figure 5, 61l! This will be explained with reference to I. Surface orientation (1
00) on a single-crystal Si substrate 1 with a thickness of 1500 nm.
Two patterns of iOz film were formed using the LOCOS method, and this was planarized using a general planarization technique. After normal wet cleaning, the substrate surface is cleaned by heat treatment in an ultra-high vacuum, and amorphous g
A tSi film 3 was deposited (FIG. 5(a)). 600℃, 1
This was made into a single crystal by solid phase epitaxial growth using heat treatment for 0 hours (Figure 5(b)). Next, F will be introduced here by ion implantation, but it is difficult to implant it directly into the surface layer of 300 people. Therefore, a Sift film 13 with a thickness of 1700λ was formed on this film using the CvL method, and F ions were implanted through this film (Fig. 6). The F concentration in the Si film 7 is 5 x 105' Cal -''.
A heat treatment was performed at ℃ for 30 minutes to sufficiently distribute F to the crystal defects in the Si film 7 (inactivation of defects in the IMI Silo). CVD-SiOafl by soaking in HF aqueous solution! After removing J13, the substrate surface was cleaned by a combination of normal wet cleaning and heating in an ultra-high vacuum. On the surface of this substrate, amorphous Si3 was deposited to a thickness of 700 nm by electron beam heating evaporation in an ultra-high vacuum (51st pl(c)). 600℃
By performing heat treatment for 30 minutes at
Figure 5(d)). A high quality Si ultra-thin film crystal 8 was obtained on the SiOx film 2 (Fig. 5(e)). (Example 9) A film with a thickness of 150 mm was deposited on a single crystal Si substrate l with a plane orientation (Zoo).
Two patterns of 0λ 5iOx film are formed by LOCOS method,
This was flattened using common flattening technology. Afterwards, the substrate surface was cleaned using a combination of conventional wet cleaning and heating in an ultra-high vacuum. Immediately, electron beam heating evaporation was performed in an ultra-high vacuum using F ionization doping to form an amorphous Si film 3 containing 8 x 10 cm of F with a thickness of 22 OA on the substrate (No. 5 Figure (a)).This was heat-treated at 600℃ for 10 hours to cause horizontal phase epitaxial growth (Figure 5(b)).It was made into a single crystal. Amorphous Si (thickness 700λ) was deposited by electron beam heating evaporation in vacuum (Fig. 5(C)).
．． This was heat treated at 600°C for 20 minutes. Figure 1(d)
Vertical solid-phase epitaxial growth was caused in the manner shown in Figure 5 (d), and a high quality ultra-thin film crystal 8 was obtained on the Sins film 2 (Figure 5 (e)). Note that F has the effect of suppressing solid phase epitaxial growth (reducing the growth rate). However, as in this example, F
If the concentration is less than l x 10 ``cs-'', this effect is small and has no practical effect. (Example 10) A film with a thickness of 150 mm was deposited on a single crystal SiMI plate 1 with a plane orientation (l00).
A 0A SiOz Ili2 pattern was formed using the LOCOS method. The substrate surface was cleaned using a cleaning technique combining conventional wet cleaning and heating in an ultra-high vacuum, and an amorphous Si film 3 with a thickness of 3000 nm was deposited by electron beam heating evaporation in an ultra-high vacuum. This was crystallized by lateral solid-phase epitaxial growth induced by heat treatment at 600°C for 10 hours. On top of this, a thickness of 60 mm was applied using the 11-beam evaporation method.
After forming an amorphous IMS i fJ 3 and densifying it by low-temperature heat treatment (450°C, 1 hour), it was introduced into an ion implanter. By performing multiple ion implantation as in Example 3 or 4, U is almost uniformly implanted into the Si film 7 crystallized in the previous step.
Introducing e (germanium) and increasing its concentration to IXIO”5
It was set as m−δ. By heat-treating this at 600° C. for 1 hour, the Si layer 15 deposited for the second time by vertical solid-phase epitaxial growth was crystallized as shown in FIG. Since this crystal 8 made with a certain length in the vertical direction contains Ge, it does not carry any crystal defects of the underlying seed crystal layer 7, resulting in an extremely high quality crystal. (Example 11) A film with a thickness of 1500 mm was deposited on a single crystal Si substrate 1 with an orientation of (100).
Two patterns of SiOz films with a wavelength of 2,700 amorphous Jl
¥Si film 3 was deposited. This was crystallized by lateral solid-phase epitaxial growth induced by heat treatment at 600°C for 10 hours. On top of this, a thickness of 4000λ was applied using the electron beam evaporation method.
An amorphous Si film 3 of
After being densified for 1 hour), it was introduced into an ion implantation device. Project range (Projected1{an
ga (Rp)) is ΔRp between the first layer Si7 and the second layer S
Ge ion implantation was performed by setting the implantation energy to be shallower than the interface with i3 (Figure 8). Here, the peak concentration in the Ge concentration profile NGe shown in FIG. 8 above is 2 X 10'! 'ex-8. By heat-treating this at 600°C for 1 hour, vertical solid-phase epitaxial growth occurs using the previously crystallized S i wj4 7 as a seed crystal, and the second deposited amorphous Sij%3 is crystallized. However, at this time, the crystal defects that had extended from the seed crystal during growth were blocked by the Go-doped Jl15 and could not go above it, resulting in a defect-free Si crystal layer above it. This is a simple method of Example 10, in which Ge ion implantation is done only once. However, it has slightly lower thermal stability than Example 10, so it is preferable to use it in applications that do not require high heat treatment. (Example 12) Rhinoceros 150
0 people (1) S i O 2wI4ha9 - N't-
This was then flattened using a general flattening technique.Then, the substrate surface was cleaned by a combination of ordinary wet cleaning and heating in an ultra-high vacuum. Then, an amorphous Si film 3 with a thickness of 300 nm was formed by electron beam heating evaporation in an ultra-high vacuum (see Fig. 5(a)).
))． A heat treatment at 600°C (performed for 10 hours) caused lateral solid-phase epitaxial growth, and amorphous Si[3 was crystallized (Fig. 5(b)). After this. An amorphous Si film 3 with a thickness of 700λ was formed on the substrate by electron beam heating evaporation in an ultra-high vacuum using Ga ionization doping (
Figure 5(c)). ae concentration is 1.3XIO503″″8
It is. By heat-treating this sample at 600°C (30 minutes), vertical solid phase epitaxial growth occurs as shown in Figure 7, and as shown in Figure 5(d)), the second deposited film 15 is crystallized. did. As a result, an ultra-thin Si crystal without crystal defects could be obtained on the Sift film 2 (FIG. 5C)). (Example 13) On a single-crystal Si substrate 1 with a plane orientation of (100),
Two patterns of SiOz film were formed using the LOCOS method.
This was flattened using general flattening technology. Afterwards, the substrate surface was cleaned using a combination of conventional wet cleaning and heating in an ultra-high vacuum. On this substrate, electron beam heating evaporation of Si using a combination of H ionization doping and F ionization doping was performed in an ultra-high vacuum to a thickness of 270A.
Amorphous Si f4 3 was formed (Fig. 5(a)).
．． At this time, the B concentration and FWA degree are 2×1057cm-” (2×10173″a), 5, respectively.
×10173-8. Subsequently, heat treatment at 600°C (1
0 hours) and crystallized by lateral in-phase epitaxial growth (Fig. 5(b)). On top of this, an amorphous Si film 3 with a thickness of 700 mm was formed using an electron beam heating evaporation method in an ultra-high vacuum using Ge ionization doping. be. By heat treating this sample at 600°C (30 minutes), the 7th L! ! A vertical solid-phase epitaxial elongation was performed as described in step 4, and the second deposition was carried out (i
SiNII15 containing e was crystallized, and As a result,
A high-quality ultra-thin Si crystal 8 free of crystal defects could be obtained on the Sins film 2 through Si[7 with crystal defects inactivated. We conducted an experiment with P instead of H and confirmed its effectiveness. (Example 14) An example in which a second layer of Si crystal was made by a method other than solid-phase epitaxy is described.A SiOz* pattern with a thickness of 1500A was formed by LOCOS on a single crystal Si substrate 1 with a plane orientation of (100).
Formed by law. The substrate surface was cleaned by a combination of conventional wet cleaning and heating in an ultra-high vacuum. A thickness of 27 cm was deposited on this substrate by electron beam heating evaporation in an ultra-high vacuum.
An amorphous Si film 3 of 00A was formed. The amorphous Si film 3 was crystallized by lateral solid-phase epitaxial growth by heat treatment at 600°C (8 hours) in the same ultra-high temperature environment. The temperature of this substrate was raised to 750°C, and Si was deposited by electron beam heating. The technique of vapor deposition in an ultra-high vacuum while heating the substrate is called molecular beam epitaxy, in which Si deposition and crystallization proceed simultaneously. Now it's 430
A single-crystal sikI17 of 0.00% was formed on the substrate (Fig. 9). (Example 15) Another example in which a second round of Si crystal was produced by a method other than solid phase epitaxy will be described. That is, the second scrap was formed by vapor phase epitaxial growth. Single crystal S with plane orientation (100)
On the i-substrate 1, 2 patterns of SiO thin film of 1500 rhinoceros were formed using the LOCOS method. The substrate surface was cleaned by a combination of conventional wet cleaning and heating in an ultra-high vacuum. On this substrate, an amorphous 81 film 3 with a thickness of 2500 μm was formed by electron beam heating evaporation in an ultra-high vacuum. Similarly, heat treatment at 600°C (8 hours) was performed in an ultra-high vacuum, and Wt
In-phase epitaxial growth occurs. Amorphous Si film 3
was crystallized.

This sample was placed in a quartz reaction tube and vapor phase epitaxial growth was performed. First, in order to clean the surface of the Si film 7 that has been crystallized by lateral growth, the temperature of the sample is lowered to 1.
Raised to 100℃. Exposure to Hz gas for 30 minutes. Next, the sample temperature was lowered to 1000°C, SiH4 gas was flowed into the reaction tube, and S was formed on the crystal film 7 by the decomposition and reaction of SiHa.
i was deposited (1 μm). Under these conditions, crystal growth occurs concurrently with Si deposition (vapor phase epitaxial growth). In this way, a crystal 18 was obtained by vertical growth on the horizontally grown film 7 (FIG. 10). (Example 16) On the Sol substrate produced in Example 1, ordinary MOS (Metal-Oxi
de-Semiconductor) type? '
E T (Field-Heffect-Tr
n-channel MOS-FE'r and P-channel MOS-F'E'r were fabricated using the fabrication process (field effect transistor) (11th
Figures (a) and (b)) - Gate lengths of 1.2 μm and 2 and 4.8 μm were made, respectively. In all cases, the in-channel electron mobility is 600 d/v-s or more, the hole mobility is 200 aJ/V-s or more, and the leakage current is IX10'.
Good characteristics of less than 13A/μm were obtained. (Example 17) On the ultra-thin Sol substrate fabricated in Example 13, an n-channel MOS was fabricated using a normal MOS/?'E'r fabrication process.
S-Fk:T (8 implanted board), P channel MOS
- 1/E'r (P implanted substrate) was produced (12th
Figures (a) and (b), respectively). We made gate lengths of 1.2 pm, 4 μm, and 8 μm. In-channel electron mobility is 1200 aJ/V-s or more, hole mobility is 400 a#/V-s or more, and leakage current I
Good cord characteristics of less than X 10-lsA/μm were obtained. (Example 18) Single-crystal Si substrate 1 with (1 1 0) plane orientation is (100)
The process of Example 1 was performed in place of the substrate. (10
Instead of a certain length in the vertical direction at 0), there is a length in the vertical direction on the (1 1 0) plane, and the lateral growth S i
A vertically elongated Si layer 8 was obtained on M'/. (1 1
Since the growth was on the (0) plane, the crystallinity was slightly inferior to the vertically grown M8 of Example 1, which was grown on the (100) plane, but the growth was not localized in the vertical direction. Minute. (1
10) A crystal powder 8 with fewer defects than a crystal formed with a certain length of facets in the lateral direction was obtained. In addition, in any of Examples 1 to 18, amorphous Si
It is noted here that when forming the film 3, other amorphous Si formation methods, such as the CvL method, may be used instead of the ultra-high vacuum vapor deposition method. [Effects of the Invention] According to the present invention, the following effects can be obtained. During growth in the vertical direction or on the (100) plane, it is possible to form a high-quality Si crystal film by preventing crystal defects from entering from the seed crystal. Furthermore, defects in the seed crystal pair can be effectively removed by controlling the potential of the seed crystal layer by introducing electrically active impurities, and by inactivating defects in the seed crystal by introducing doping. , it is possible to effectively form high-quality Sol crystals. The above effects can be obtained regardless of the thickness of the Si film, resulting in a high quality ultra-thin film! ! I! SOI crystals can be obtained.

[Brief explanation of drawings]

Figure 1, 5L! fl, 6Ij4, FIG. 8 is a cross-sectional view showing a process of creating an SQL structure according to an embodiment of the present invention, FIG. 2 is a perspective view showing the state of lateral solid phase epitaxial growth, and FIG. 3 is a conventional A cross-sectional view showing the growth process of the S01 structure by the two-phase method and a perspective view showing the state of lateral solid-phase epitaxial growth, and Figure 4 is a cross-sectional view showing the state of vertical solid-phase epitaxial growth. ! 4, FIG. 7, FIG. 9, and FIG. 10 are sectional views of SOI structures according to embodiments of the present invention, and FIGS. 11 and 12 are sectional views of semiconductor devices according to embodiments of the present invention. 1... Single crystal Si substrate, 2... Insulating film, 3...
・Amorphous Si, 4...Solid phase epitaxial, 5.
... High and small purity concentration layer, 6... Non-doped layer, 7...
Single crystal wIi (crystal film made by lateral growth) used as a seed product, 8...SQL crystal made by vertical growth, 9
... Polycrystalline Si, 10... Si layer deposited for the first time, 11... Facet, 12... Si crystal made with a certain length in the vertical direction, 13... SiOz deposited by CVL).
14...Full ion implantation, 15...Si layer into which Ge is introduced, l6...Ga ion implantation, 17...
Si crystal film formed by molecular beam epitaxy, 18...
Si crystal film formed by vapor phase epitaxy, 19...source electrode, 20...gate electrode, 21...drain electrode, 22...A s A concentration region, 23...B high concentration region. 1st Kuchibōl Concave rate 3<C) Haya 4 Machihaya 5 Kuchibashi 5 Kai (e) 3 Tate 6 Nissho 7 Kaitei 8 Kuchisou 9 Imperial brother/O Kyōl 7 Haya 1/day

Claims (1)

[Claims] 1. A multilayer film comprising a crystal film on an insulating film, and a crystal film on top of the crystal film having the same crystal orientation as the crystal film and lower crystal defect density than the crystal film. 2. The multilayer film according to claim 1, wherein the crystal film is a semiconductor. 3. Forming an insulating film with an opening on a single crystal substrate,
An amorphous film is formed thereon, part or all of the amorphous film is made into a single crystal by heat treatment, and a crystal thin film is formed on the single crystal film by epitaxial growth using this single crystal film as a seed crystal. A method for forming a crystal thin film characterized by the following. 4. The method of forming a crystalline thin film according to claim 3, wherein the single crystal and amorphous materials are semiconductors. Formation of a crystal thin film according to claim 3, characterized in that a solid phase epitaxial growth method 5 is used as a growth method, and a solid phase epitaxial growth method is used as an epitaxial growth method using the single crystal film as a seed crystal. Method. 6. Adding an impurity that can electrically activate the semiconductor used in the seed crystal to 1×1016 to 1×10Z in the seed crystal.
5. The method for forming a crystalline thin film according to claim 4, wherein the crystal thin film is contained at a concentration of 2al-3. 7. In the single crystal thin film used as the seed crystal, an element having a higher electronegativity than the elements constituting the film is added at 1×10
5. The method for forming a crystalline thin film according to claim 4, wherein the crystal thin film is contained at a concentration of 1×10Z1cs-3. 8. The epitaxially grown film using the single crystal semiconductor film as a seed crystal contains an element having a larger atomic radius than the constituent elements of the grown film at a concentration of 1×101 to 5×10111. A method for forming crystalline thin films. 9. A method for manufacturing a semiconductor device, characterized in that the crystal film according to claim 4 is used as a substrate. 10. The method for forming a crystalline thin film according to claim 4, wherein a single crystal semiconductor substrate having a plane orientation other than (111)±10° is used.