KR101669444B1 - Method of Crystal Growth of SiC Using Liquid Phase Techniques - Google Patents
Method of Crystal Growth of SiC Using Liquid Phase Techniques Download PDFInfo
- Publication number
- KR101669444B1 KR101669444B1 KR1020140016529A KR20140016529A KR101669444B1 KR 101669444 B1 KR101669444 B1 KR 101669444B1 KR 1020140016529 A KR1020140016529 A KR 1020140016529A KR 20140016529 A KR20140016529 A KR 20140016529A KR 101669444 B1 KR101669444 B1 KR 101669444B1
- Authority
- KR
- South Korea
- Prior art keywords
- seed
- sic
- growth
- protective film
- present
- Prior art date
Links
Images
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Crystallography & Structural Chemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Inorganic Chemistry (AREA)
Abstract
A method for growing a SiC single crystal based on a liquid phase growth method is disclosed. The present invention provides a method for producing a SiC seed, comprising: providing a SiC seed wherein at least a portion of the surface is coated with a protective film; Providing a growth crucible comprising a raw material powder comprising silicon; And melting the raw powder of the growth crucible and growing the SiC crystal with the SiC seed while the SiC seed is dipped in the melt. According to the present invention, it is possible to provide a method of growing a SiC single crystal capable of maintaining defects including particle defects that can occur during liquid-phase growth from a seed at a low density.
Description
The present invention relates to a method of growing a SiC single crystal, and more particularly, to a method of growing a SiC single crystal using a liquid phase technique.
SiC single crystals are used as SiC or III-nitride-based electronic devices or substrates for optoelectronic devices operating in the high power, high frequency, high temperature and blue / ultraviolet spectrum regions.
The SiC single crystal is a physical vapor transport method using a standard method. However, while significant advances have been made, SiC formed by the PVT method still exhibits a significant number of defects such as micropipes, dislocations and parasitic polytypes.
Other major semiconductors such as Si, GaAs and InP are produced by solution growth from molten metal such as Czochralski, LEC (liquid encapsulation) and VGF (verticle gradient freeze). However, the method of growing SiC single crystal is preferred for thermodynamic reasons It has been considered not. This is because a temperature of at least 3200 ° C and a pressure of 100,000 bar are required to provide a stoichiometric melt for SiC growth.
Recently, a solution having a solubility to C such as Si or Si: Cr or Si: Sc is used to produce a molten metal, and the solution growing method can be applied at a temperature of around 2000 ° C or lower.
SiC crystals prepared by the solution growth method have been reported to be useful for the generation of parasitic polytype defects during growth and the removal of micropipes present in seeds, compared with SiC crystals produced by vapor deposition.
However, the quality of the crystals grown in the solution growth method is greatly influenced by the surface state of the seed in which the initial growth takes place, so the surface state of the seed before growth is very important. For example, in the case of a growth method such as top seeded solution growth (TSSG), contamination may occur during the process of bonding the seed to the graphite holder, and contamination by the in-furnace contaminants may occur during the heating step.
In order to solve the problems of the prior art, it is an object of the present invention to provide a method of growing a SiC single crystal having a low defect during liquid crystal growth.
It is another object of the present invention to provide a method for producing a seed for use in the aforementioned SiC single crystal liquid phase growth method.
It is another object of the present invention to provide a seed for growing SiC single crystal produced by the above-described production method.
According to an aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: providing a SiC seed having at least a portion of a surface thereof coated with a protective film; Providing a growth crucible comprising a raw material powder comprising silicon; And melting the raw powder of the growth crucible and growing the SiC crystal with the SiC seed while the SiC seed is dipped in the melt.
In the present invention, in the SiC crystal growing step, the protective film of the SiC seed can be dissolved in the dipped state in the melt.
The SiC crystal growing step may include: charging the SiC seed into the growth crucible; And dipping the SiC seed in the melt together with melting of the raw powder of the growth crucible.
In the present invention, the SiC crystal growing step may include: melting the raw material powder of the growth crucible; And dipping the SiC seed in the melt of the growth crucible.
In the present invention, the raw material powder is preferably a mixed powder of silicon and aluminum.
Further, in the present invention, it is preferable that the growth crucible includes graphite.
In the present invention, the protective film of the SiC seed includes a metal oxide, preferably silicon oxide.
In the present invention, the protective film of the SiC seed preferably has a thickness of 0.5 to 1 micrometer.
According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, including: providing a SiC single crystal seed; And forming a protective film containing a metal oxide on at least a part of the SiC single crystal seed.
In the present invention, the protective film forming step may include: providing a protective film containing a metal oxide on a surface of the SiC single crystal seed; And removing a portion of the protective film.
According to another aspect of the present invention, there is provided a semiconductor device comprising: a SiC single crystal core; And a metal oxide film formed on at least a part of the surface of the SiC single crystal core.
In the present invention, the metal oxide film may include silicon oxide.
According to the present invention, it is possible to produce a high-quality SiC single crystal having a low defect density, such as trapped particles, during liquid crystal growth. According to the process of the present invention, it is possible to manufacture a SiC single crystal having a high crystallinity by suppressing the possibility of occurrence of defects without applying a complicated process condition or a process environment.
FIG. 1 is a diagram schematically showing an apparatus for growing a SiC single crystal according to a preferred embodiment of the present invention.
2 is a flow chart schematically illustrating a growth procedure of a SiC single crystal according to a preferred embodiment of the present invention.
FIG. 3 is a view showing an exemplary heat treatment schedule of the present invention. FIG.
4 is an optical microscope photograph of a surface of a SiC seed which is not subjected to surface treatment.
5 is a diagram schematically showing the cause of the particle trapping phenomenon in FIG.
6 is a diagram schematically showing a cross section of a seed having a protective film formed according to the present invention.
Fig. 7 is a view showing an example of a procedure for producing a SiC seed according to the present invention.
8 is a diagram schematically showing an etched seed section according to an embodiment of the present invention.
Fig. 9 is an optical microscope photograph showing the protective film non-formation region A of the SiC single crystal observed.
Fig. 10 is an optical microscope photograph of the protective film forming region (B) of the SiC single crystal observed.
It is an object of the present invention to provide a solution growth method of a SiC single crystal according to a preferred embodiment of the present invention.
1 is a diagram schematically showing an apparatus for growing a SiC single crystal according to a preferred embodiment of the present invention.
1, the
Preferably, the
The
The carbon source originating from the melting crucible, the inner wall of the chamber, the heating heater, and the like is dissolved as a solute in the molten raw material powder during the heating process, and as a result, the molten metal containing carbon serves as a source of SiC crystal growth.
The
2 is a flow chart schematically illustrating a growth procedure of a SiC single crystal according to a preferred embodiment of the present invention.
Referring to FIG. 2, a predetermined surface-treated
As described later, in the present invention, the SiC seed has a protective film on its surface. This will be described later.
On the other hand, raw powder is prepared in the
At least a portion of the seed is dipped into the melt of the crucible at or near the melting temperature of the raw material powder or at a predetermined crystal growth temperature (S118). As described below, the preferred dipping point can be designed to minimize contaminants.
As an example, in the present invention, dipping can be performed after the crystal growth temperature is different. Alternatively, the seed may be dipped either simultaneously with or immediately after melting of the mixed powder. For example, if seeds mounted on the seed holder are charged in the growth crucible and the seed is placed at the expected dipping position, dipping can be performed simultaneously with melting of the raw material powder. This method can mitigate trapping of contamination by vapor deposition which may occur before solution growth.
The seed is dipped and crystal growth is started at the crystal growth temperature (S120), and the temperature of the
When the crystal growth is completed, the crystal containing the seed is pooled to separate the seed from the molten metal (S122).
Although the crystal growth method of the present invention has been described based on TSSG (top seeded solution growth), the method of the present invention is not limited thereto. For example, a traveling heater method (THM), a traveling solvent method (TSM), a slow cooling method, or the like may be used.
FIG. 3 is an exemplary diagram illustrating a heat treatment schedule including a temperature raising process of the present invention.
Referring to FIG. 3, a crystal growth temperature of 1800 DEG C is illustrated. The temperature rise to the crystal growth temperature consists of a steep temperature rise up to about 1320 ° C and a gentle warming up to the crystal growth temperature thereafter. After about 2 hours at the crystal growth temperature, the annealing process may proceed according to the schedule shown.
Fig. 4 is an optical micrograph showing the surface of a seed held without dipping in a molten metal according to a predetermined heat treatment schedule after loading into the apparatus described with reference to Fig. 1 using a normal SiC seed not subjected to a special surface treatment to be. Si + 20wt% Al was used as the molten metal, and the heat treatment was performed after the temperature was elevated to 1800 ° C.
Figure 4 shows the unintentional closing of particles or impurities in crystals that occur when applying conventional SiC solution growth methods. The particle entrapment phenomenon described above is predicted to be caused by pollutants generated during the heating process.
5 is a diagram schematically showing the cause of the particle trapping phenomenon in FIG.
Referring to FIG. 5, various contaminants that have been vaporized or sublimated from the raw powder or chamber before and after the formation of the molten metal during the heating process are shown. For example, the source may be carbon, Al, Si or other material.
In the solution growth method, it takes a considerable time to raise the temperature to the crystal growth temperature. Before the dipping into the molten metal, a SiC layer is formed on the surface of the seed by the physical vapor deposition mechanism . In this case, the contamination source can not be removed from the inside of the crystal, and particle trapping phenomenon as shown in FIG. 4 may be caused.
In order to solve such problems, the inventors of the present invention solve the problem of particle trapping by forming a passivation layer on the surface of the SiC seed.
The protective layer protects the seed surface during the heating process for solution growth. In addition, the protective film is temporarily removed from the crystal growth process while protecting the crystal surface temporarily during the temperature raising process. For example, it is preferable that the protective film is dissolved and dissolved in the molten metal upon dipping.
In addition, it is preferable that the protective film is selectively etchable by a physicochemical method after deposition. For example, it may be preferable that the protective film on the upper part of the seed, which is bonded to the seed holder in the protective film, is selectively removed for bonding.
In order to secure the above-described protective function and selective removal easiness, a metal oxide film may be used as the protective film. Preferably, the protective film preferably comprises SiO 2. Of course, metal oxides such as Ti, Al, Cr, Mn, Ni and Fe may be used instead.
6 is a diagram schematically showing a cross section of a seed having a protective film formed according to the present invention.
Referring to FIG. 6, a
In addition, the thickness of the protective film in the present invention is preferably in the range of 0.5 to 1 micrometer. The protective film must remain in the gas phase before the solution is added to the solution, and a suitable thickness is required so that rapid etching can take place after being added to the solution.
Fig. 7 is a view showing an example of a procedure for producing a SiC seed according to the present invention.
Referring to FIG. 7, a metal oxide film such as a SiO 2 oxide film is formed on the entire surface of a SiC seed according to a conventional deposition method such as Chemical Vapor Deposition (CVD) (100). Subsequently, a mask pattern such as a photoresist is formed on the surface of the seed, preferably including the dipping portion of the seed (102). Next, the exposed SiO 2 film is removed using the mask pattern as an etching mask to expose the seed surface (104). For etching, a conventional etching method such as wet etching or dry etching may be used. When the etching is completed, the mask pattern is removed.
By using the SiC seed having the protective film pattern formed as described above, the crystal growth surface is protected in the step before the dipping of the seed. As described above, the SiO 2 protective film is dissolved and dissolved in the molten metal upon dipping into the molten metal.
Accordingly, the protective film protects the growth surface of the seed before the crystal growth and prevents adhesion of the contamination source.
In the present invention, the seed having the above-described protective film can be attached to the seed holder in an appropriate manner. A carbon adhesive conventionally used for bonding the seed and the seed holder may be used. Alternatively, other carbon sources, such as photoresists, may be used as adhesives.
<Examples>
SiC seed (area: 1 cm x 1 cm, thickness: 350 μm) of Dow Corning Inc. was formed on the seed surface by chemical vapor deposition to form a SiO 2 protective film. The thickness of the protective film was about 1 micrometer. The deposition conditions were 550 mTorr of process pressure, RF power of 60 W, gas flow rates of SiH 4 , N 2 O and
Subsequently, AZ1512 photoresist solution of Dow was applied and a portion of the seed was exposed using a UV light source. Then, the exposed protective film area was etched using a buffered oxide etchant (BOE). 8 is a diagram schematically showing a cross section of a seed formed through an etching process. As shown in the figure, it can be seen that the seed surface is exposed in the region A on the seed bottom and the seed surface is covered by the protective film in the region B with respect to the center of the seed.
Then, the upper surface of the produced SiC seed was attached to the seed holder. A photoresist was used as an adhesive in the bonding of the seed and the seed holder. A photoresist was applied to the top surface of the seed and heat treated at a temperature of about 1200 캜 for 2 hours to bond the seed holder and the seed.
Si powder of Tae Won Scientific Co. and Al powder of Tae Won Scientific Co. were prepared and mixed at 8: 2 by weight ratio to prepare a raw material powder. The raw material powder thus prepared was placed in a growth crucible and mounted on the growth furnace of Fig. 1 together with the seed. The growth furnace was maintained at a high vacuum of about 8 × 10 -3 torr and the temperature was raised in accordance with the heat treatment schedule of FIG. The seed was dipped in a melt at 1800 ° C, which was a crystal growth temperature, and crystal growth was performed for about 2 hours. Subsequently, the seed was pulled in a molten bath and cooled according to the heat treatment schedule of FIG. The resultant single crystal was washed with a solution of hydrofluoric acid, nitric acid and heavy water (weight ratio 1: 3: 4).
The washed crystals were surface-analyzed by an optical microscope and a nano-view surface profiler of Nano System Co., Ltd., and the growth thickness was measured by a FEED-SEM (FeildEmmission Scanning Microscopy) of Hitachi. Surface defects were also analyzed by KOH etching.
Figs. 9 and 10 are optical microscope photographs showing the protective film non-formation region (A) and the protective film formation region (B) of the SiC single crystal obtained in each example.
9, TD (Threading Dislocation) and BPD (Basal Plane Dislocation) are observed at the respective points (# 4, # 5, # 6) of the protective film non-formation region. 10, TD is observed at each of the points (# 1, # 2, # 3) in the protective film forming region, but the frequency is significantly decreased as compared with FIG. In addition, it can be seen that no BPD is observed at each point of the protective film forming region.
On the other hand, the number of etch pits was calculated after the surface of the single crystal was etched using a KOH solution.
Table 1 below is a table summarizing the defect density measured at each point in each of the areas A and B.
From the above table, it can be seen that EPD (etch pit density) is increased by about 80% when a protective film is not formed.
As described above, it can be seen that the protective layer provided on the seed surface as in the present invention significantly reduces the defect density of the SiC single crystal in the solution growth method.
10 SiC seed
20 Shield
100 single crystal growth device
110 heating heater
120 Growing Crucible
122 melt
130 seed holder
140 chamber
Claims (14)
Providing a growth crucible comprising a raw material powder comprising silicon; And
Melting the raw powder of the growth crucible and firing the SiC crystal with the SiC seed while the SiC seed is dipped in the melt,
Wherein the protective film of the SiC seed comprises a metal oxide,
Wherein the protective film of the SiC seed is dissolved in the molten liquid in a dipped state.
In the SiC crystal growing step,
Charging the SiC seed into the growth crucible; And
And dipping the SiC seed in the melt together with melting of the raw powder of the growth crucible.
In the SiC crystal growing step,
Melting the raw material powder of the growth crucible; And
And dipping the SiC seed in the melt of the growth crucible.
Wherein the raw material powder is a mixed powder of silicon and aluminum.
Wherein the growth crucible comprises graphite.
Wherein the protective film of the SiC seed comprises silicon oxide.
Wherein the protective film of the SiC seed has a thickness of 0.5 to 1 micrometer.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR1020140016529A KR101669444B1 (en) | 2014-02-13 | 2014-02-13 | Method of Crystal Growth of SiC Using Liquid Phase Techniques |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR1020140016529A KR101669444B1 (en) | 2014-02-13 | 2014-02-13 | Method of Crystal Growth of SiC Using Liquid Phase Techniques |
Publications (2)
Publication Number | Publication Date |
---|---|
KR20150095344A KR20150095344A (en) | 2015-08-21 |
KR101669444B1 true KR101669444B1 (en) | 2016-10-26 |
Family
ID=54058387
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
KR1020140016529A KR101669444B1 (en) | 2014-02-13 | 2014-02-13 | Method of Crystal Growth of SiC Using Liquid Phase Techniques |
Country Status (1)
Country | Link |
---|---|
KR (1) | KR101669444B1 (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10196315B2 (en) * | 2017-01-11 | 2019-02-05 | General Electric Company | Melt infiltration with SiGa and/or siln alloys |
KR102665190B1 (en) * | 2019-07-19 | 2024-05-09 | 주식회사 엘지화학 | Manufacturing method of single crystal |
CN113005519B (en) * | 2021-02-26 | 2022-07-01 | 哈尔滨科友半导体产业装备与技术研究院有限公司 | Method for growing silicon carbide crystal by adopting pretreatment seed crystal |
CN113026105B (en) * | 2021-02-26 | 2022-07-05 | 哈尔滨科友半导体产业装备与技术研究院有限公司 | Growth method for preparing silicon carbide crystal by using pretreated powder |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010514648A (en) * | 2006-09-14 | 2010-05-06 | クリー インコーポレイテッド | Micropipe-free silicon carbide and method for producing the same |
JP2013256445A (en) | 2013-08-21 | 2013-12-26 | Shin-Etsu Chemical Co Ltd | Method for producing single crystal silicon |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4450075B2 (en) * | 2008-01-15 | 2010-04-14 | トヨタ自動車株式会社 | Method for growing silicon carbide single crystal |
KR101081598B1 (en) * | 2009-02-06 | 2011-11-08 | 동의대학교 산학협력단 | Treatment method for seed and growing mehtod for single crystal |
-
2014
- 2014-02-13 KR KR1020140016529A patent/KR101669444B1/en active IP Right Grant
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010514648A (en) * | 2006-09-14 | 2010-05-06 | クリー インコーポレイテッド | Micropipe-free silicon carbide and method for producing the same |
JP2013256445A (en) | 2013-08-21 | 2013-12-26 | Shin-Etsu Chemical Co Ltd | Method for producing single crystal silicon |
Also Published As
Publication number | Publication date |
---|---|
KR20150095344A (en) | 2015-08-21 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP4100228B2 (en) | Silicon carbide single crystal and manufacturing method thereof | |
KR101960209B1 (en) | Method for producing silicon carbide single crystal ingot and silicon carbide single crystal ingot | |
JP5429288B2 (en) | Method for producing SiC single crystal | |
US9587327B2 (en) | Method of production of sic single crystal | |
KR101669444B1 (en) | Method of Crystal Growth of SiC Using Liquid Phase Techniques | |
KR101152857B1 (en) | Method for growing silicon carbide single crystal | |
JP7085833B2 (en) | Method for manufacturing silicon carbide single crystal | |
JPH09268096A (en) | Production of single crystal and seed crystal | |
JP2015182948A (en) | Production method of silicon carbide single crystal | |
JP5850490B2 (en) | Method for producing SiC single crystal | |
JP5614387B2 (en) | Silicon carbide single crystal manufacturing method and silicon carbide single crystal ingot | |
JP6028754B2 (en) | Method for manufacturing SiC single crystal substrate | |
JP4253974B2 (en) | SiC single crystal and growth method thereof | |
WO2009107188A1 (en) | METHOD FOR GROWING SINGLE CRYSTAL SiC | |
KR101081598B1 (en) | Treatment method for seed and growing mehtod for single crystal | |
KR101983751B1 (en) | Method for regenerating member within silicon single crystal pulling apparatus | |
JP2000034199A (en) | Production of silicon carbide single crystal | |
JP2005132703A (en) | Method for manufacturing silicon carbide substrate, and silicon carbide substrate | |
JPH0797299A (en) | Method for growing sic single crystal | |
JPH0977595A (en) | Production of silicon carbide single crystal | |
KR101409424B1 (en) | Method for decreasing defects of silicon-carbide seed | |
JP2010052997A (en) | Production method of seed crystal for growth of silicon carbide single crystal, and production method of silicon carbide single crystal | |
JP2002274995A (en) | Method of manufacturing silicon carbide single crystal ingot | |
JP4200690B2 (en) | GaAs wafer manufacturing method | |
KR101553386B1 (en) | Nitrogen gas passivation method for seed and method for growing single crystal using the same |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
A201 | Request for examination | ||
E902 | Notification of reason for refusal | ||
E902 | Notification of reason for refusal | ||
E701 | Decision to grant or registration of patent right | ||
GRNT | Written decision to grant | ||
FPAY | Annual fee payment |
Payment date: 20191015 Year of fee payment: 4 |