CN1184669C - Chemical vapor deposition growth method of silicon germanium/silicon - Google Patents

Abstract

The invention discloses a method for epitaxially growing silicon germanium/silicon material by using photochemical vapor deposition equipment under the technological environment of low temperature and ultrahigh background vacuum degree. The main feature of the present invention is that the advantages of UHV/CVD technology and optical CVD technology are organically combined, the vacuum degree in the background is better than 1×10 ^-7 Pa, the reaction temperature is 400-450°C, and the reaction pressure is 1-10Pa. Next, grow silicon germanium/silicon material. The silicon germanium/silicon material grown by the invention not only has small stress and complete crystal structure, but also has good interface properties and meets practical requirements.

Description

Chemical vapor deposition growth method of silicon germanium/silicon

Technical field

The invention belongs to the technical field of chemical vapor deposition growth of crystal materials, in particular to a chemical vapor deposition epitaxial growth method of semiconductor thin film materials.

technical background

With the development of semiconductor technology, some new semiconductor materials have appeared in recent years, and silicon germanium (SiGe) alloy is one of them. Since changing the germanium composition in the alloy can tailor the bandgap width of the silicon germanium (Si _1-x Ge _x ) material, the new material silicon germanium/silicon (Si _1-x Ge _x /Si) obtains special physical properties and electrical properties characteristics are valued by people. As long as the mature silicon (Si) process technology is adopted, new microelectronic and optoelectronic devices can be easily produced using Si _1-x Ge _x materials, among which Si _1-x Ge _x /Si heterojunction devices are characterized by their ultra-high speed, The advantage of low cost poses a strong challenge to the traditional silicon and gallium arsenide technology. Some international group companies, including IBM and Mercedes-Benz, have invested a lot of money in researching the growth technology of Si _1-x Ge _x materials and Device design, manufacturing technology and application. Devices and circuits based on Si _1-x Ge _x materials have been successfully developed and are becoming practical.

At present, the epitaxial growth methods of Si _1-x Ge _x /Si materials at home and abroad mainly include molecular beam epitaxy (MBE) growth technology and chemical vapor deposition (CVD) growth technology. The material grown by MBE technology has high precision, good quality, and can be controlled in real time, but the equipment is expensive, the operating cost is high, and more importantly, it is difficult to form mass production and realize industrialization. In contrast, chemical vapor deposition technology has the advantages of low deposition temperature, easy control of film composition and thickness, good uniformity and repeatability, excellent step coverage, wide application range, low technical cost, simple equipment, and mass production. And so on a series of advantages. Therefore, at present, the epitaxial growth of Si _1-x Ge _x materials at home and abroad mostly adopts CVD technology. The chemical vapor deposition technology related to the present invention includes: ultra-high vacuum chemical vapor deposition (UHV/CVD) and ultraviolet photochemical vapor deposition (UV/CVD).

UHV/CVD technology refers to the technology of depositing gas-phase substances on the surface of the substrate to form the required epitaxial layer through chemical reaction in the ultra-high vacuum system (the background vacuum should be better than 10 ^-7 Pa). higher than 600°C. UHV/CVD technology can effectively reduce the contamination of the interface between the substrate and the epitaxial layer and the contamination of impurities such as oxygen and carbon, so as to obtain high-quality silicon germanium/silicon heterojunction bipolar transistors (Si _1-x Ge _x /Si-HBT) and Si _1-x Ge _x /Si materials required by other applications. Semiconductor Journal) "Volume 22 No. 3 "Using High Vacuum/Rapid Thermal Treatment/Chemical Vapor Deposition Epitaxial SiGe HBT Structure)" reported the use of UHV/CVD technology to grow Si _1-x Ge _x /Si materials at a temperature of 550 ℃. Figure 1 is the twin crystal X-ray back-dog curve of the grown sample. UHV/CVD technology Si _1-x Ge _x /Si material growth temperature is high, which is easy to cause outdiffusion of Ge and dopant elements, resulting in unclear interface of Si _1-x Ge _x /Si material, and large interface stress, easy to form defects , affecting device characteristics. Therefore, it is still hoped that the growth temperature can be further reduced.

UV/CVD technology uses ultraviolet photon energy to dissociate the chemical bonds of gas phase reactants at low temperature, and deposits on the substrate surface through chemical reaction to form an epitaxial layer. The advantage of using UV/CVD technology is that the reaction temperature is low, and the epitaxial layer material with small stress and clear interface can be obtained. However, the disadvantage of conventional UV/CVD technology is that the background vacuum is low, which makes the epitaxial material susceptible to contamination by oxygen, carbon and other harmful impurities in the atmosphere, which affects the quality of the epitaxial layer. According to the report of J.Electronic Materials, 1990, №5, p1083, the minimum substrate temperature for growing Si _1-x Ge _xi materials by optical CVD technology is 250-300°C, but the crystal quality of Si _1-x Ge _x materials is poor .

It can be seen that the above-mentioned UHV/CVD and UV/CVD technologies have their own advantages, but for epitaxial growth, device-level Si _1-x Ge _x /Si materials with small stress, clear interface characteristics, and complete crystal structure have their own advantages. Defects and deficiencies. To meet the requirements of device-level materials, the growth of Si _1-x Ge _x /Si materials should have low temperature and ultra-high vacuum growth background conditions.

Contents of Invention

The technical problem to be solved by the present invention is to organically combine and optimize the two processes of UHV/CVD and UV/CVD epitaxial growth of Si _1-x Ge _x /Si materials, and provide a process in ultra-high background vacuum degree. Under the environment, the method of growing Si _1-x Ge _x /Si material at low temperature with the help of photon energy, and the Si _1-x Ge _x /Si material grown by this method has small stress, clear interface, and complete crystal structure, which meets the requirements of HBT. need.

In order to solve the above-mentioned technical problems, the method adopted for growing one layer of silicon germanium/silicon (Si _1-x G _x /Si) in the present invention is: using the process system developed based on the above-mentioned technology, at first the pretreated silicon substrate The negative film or the substrate with the silicon epitaxial layer passes through the processing chamber and the preparation chamber with the background vacuum step by step for final chemical cleaning and treatment, and then transfers to the vacuum reaction chamber with the background vacuum degree higher than 1×10 ^-7 Pa on the substrate, and the substrate in the reaction chamber is heated to a temperature of 400-450°C, and then the reaction gas is introduced into the vacuum reaction chamber. The reaction gas includes silane (SiH ₄ ) and germane (GeH ₄ ); the flow rate of the reaction gas Set according to the doping concentration and chemical reaction speed of the growing material, turn on the ultraviolet light source, and irradiate the reaction gas in the vacuum reaction chamber. The irradiation time depends on the thickness of the growing material. During the irradiation of the ultraviolet light source, the pressure of the vacuum reaction chamber is always Maintained at 1 ~ 10Pa.

The method for growing multi-layer silicon germanium/silicon (Si _1-x Ge _x /Si) material of the present invention is that after the first layer of Si _1-x Ge _x material is grown, immediately turn off the ultraviolet light source and stop feeding the reaction gas, Quickly pump out the residual gas trapped in the vacuum reaction chamber; switch the reaction gas and change the process conditions according to the Ge component, doping type, and growth thickness of the material to be grown, and then turn on the ultraviolet light source to perform a new layer of material Epitaxial growth: the above process is repeated according to the number of layers of silicon germanium material to be epitaxially grown.

The method for growing silicon-germanium/silicon heterojunction material of the present invention is, in the process of growing N-layer silicon-germanium/silicon material, the germane during the growth of N' material layers below the N-th layer silicon-germanium/silicon material can be The flow rate is set to zero, and N'≤N-1, the N' material layers can be continuous or discontinuous, or both continuous and discontinuous coexist.

According to the requirements of chemical reaction speed, the reaction gas introduced into the vacuum reaction chamber may also include dichlorodihydrosilane (SiH ₂ Cl ₂ ).

According to the present invention, if N-type or P-type Si _1-x Ge _x materials are to be grown, phosphine (PH ₃ ) or borane (B ₂ H ₆ ) needs to be introduced into the vacuum reaction chamber.

The chemical reaction principle of the present invention is to adopt mercury-sensitized photochemical vapor deposition technology to stimulate the reaction gas to decompose, that is to say, the 253.7nm ultraviolet photons emitted by the low-pressure mercury lamp are absorbed by mercury atoms as a sensitizer, and then utilize the The mercury ionization reaction gas in the state is deposited to form a film. In this process, the ultraviolet photons excite the mercury atoms from the ground state Hg ( ¹ S ₀ ) to the triplet state Hg ( ³ P ₁ ). The mercury atoms in this excited state have an energy exceeding 112.2 kcal/mol in the ground state. These energies can be transferred to molecules of the reaction gas, such as silane, germane, and dichlorodihydrosilane, through collisions, and the mercury atoms in the triplet excited state return to the ground state after the collision. Reactive gas molecules that have received energy undergo a chemical reaction of dissociation in the gas phase, and undergo an adsorption reaction on the surface of the silicon substrate to form the required material film. Concrete reaction process is as follows:

1)

3)

The beneficial effects of the present invention are reflected in the following aspects:

(1) The present invention absorbs the advantages of photochemical vapor deposition (UV/CVD) technology, and greatly reduces the substrate temperature during the growth of Si _1-x Ge _x /Si materials with the help of photon energy. The substrate temperature can be selected in the range of 400-450°C, which effectively avoids and reduces the unclear material interface caused by the out-diffusion of Ge and dopant elements at high temperature, wafer warpage at high temperature, and Si _1-x Ge _x / The defects caused by the interface stress of Si material can grow high-quality Si _1-x Ge _x /Si pseudomorphic structure, creating favorable conditions for device manufacturing.

(2) The present invention absorbs the advantage that the reaction chamber of UHV/CVD technology is in an ultra-high vacuum background, and the growth equipment used adopts a structure of three-stage vacuum chambers transitioning step by step. Before the reaction, the reaction chamber has a background vacuum of better than 10 ^-7 Pa, and the silicon substrate is isolated from the atmosphere since the final cleaning, which can not only keep a fresh surface of the silicon substrate during the reaction, but also effectively Avoiding the influence of harmful impurity elements in the atmosphere such as carbon and oxygen on the quality of Si _1-x Ge _x /Si materials during the material growth process, thus providing an effective guarantee for the growth of high-quality Si _1-x Ge _x /Si materials.

(3) During the chemical reaction process of the present invention, the pressure of the reaction chamber can be selected in the range of 1-10 Pa as required to adjust the reaction speed. In this way, the crystallization quality of the Si _1-x Ge _x /Si material can be improved, high-quality materials can be grown, and the growth thickness of the material can be controlled more effectively and precisely.

(4) The method adopted for the growth of Si _1-x Ge _x /Si material in the present invention is that after the growth of one layer of material is completed, the reaction can be stopped by turning off the light source, and the residual gas in the reaction chamber is quickly pumped out, and then switch The source of gas is used to grow another layer of material. Since turning off the light source will immediately stop the photodecomposition reaction, and at a substrate temperature of only 400-450°C, the residual reaction gas is difficult to thermally decompose, so it will not have an adverse effect on the grown material. For the second layer, the previous layer is still a fresh surface. Therefore, the continuously grown materials have excellent interface properties, which is beneficial to the growth of high-quality Si _1-x Ge _x /Si materials suitable for Si 1- _x Ge _x /Si-HBT and other devices.

Description of drawings

Fig. 1 is a double crystal X-ray hysteresis curve diagram of silicon germanium material grown by UHV/CVD.

Fig. 2 is a schematic diagram of photochemical vapor deposition equipment for implementing the present invention.

Fig. 3 is an X-ray diffraction diagram of the Si _1-x Ge _x /Si material grown in Example 1 of the present invention.

Fig. 4 is a secondary ion mass spectrum (SIMS) diagram of the Si _{1-x Gex} /Si material grown in Example 1 of the present invention.

Fig. 5 is a schematic diagram of the structure of the Si _{1-x Gex} /Si-HBT material layer grown in Example 2 of the present invention.

FIG. 6 is a secondary ion mass spectrum (SIMS) diagram of the Si _{1-x Gex} /Si-HBT material grown in Example 2. FIG.

Detailed ways

The present invention will be further described below through multiple examples realized on the novel photochemical vapor deposition equipment shown in FIG. 2 (this equipment has applied for a Chinese patent with application number 02262163.6).

Example 1 is to grow a layer of intrinsic silicon germanium (Si _{1-x Gex} ) material on the Si substrate, and its technological process is carried out according to the following steps:

Step 1: filling the processing chamber of the photochemical vapor deposition equipment with high-purity nitrogen to an atmospheric pressure. After the RCA treatment, the Si substrate is quickly placed in the high-purity nitrogen-protected processing chamber 3, and the processing chamber 3 is sealed;

Step 2: In the processing chamber 3, put the Si substrate into a 10% hydrofluoric acid (HF) solution through a sealed rubber glove, take it out after 30 seconds and put it into the substrate tray; at the same time, fill up the preparation chamber 4 Pure nitrogen to an atmospheric pressure, and put the tray into the preparatory chamber 4;

Step 3: respectively start the rotary vane mechanical vacuum pump and the turbomolecular pump of the three-stage vacuum system 5 of the photochemical vapor deposition equipment, and pump the vacuum degree of the preparation chamber 4 to 10 ⁻⁵ Pa;

Step 4: Simultaneously evacuate the vacuum degree of the preparation chamber 4 and the reaction chamber 1 to above 10 ^-5 Pa, send the silicon substrate into the reaction chamber 1 through the vacuum magnetic transfer rod, and then start the sputtering ion pump of the three-stage vacuum system 5, Evacuate the vacuum degree of the reaction chamber 1 to 1×10 ^-7 Pa; after that, quickly heat the Si substrate in the reaction chamber 1 to 800°C and keep it for 3 minutes to remove the natural oxide layer on the surface of the silicon wafer;

Step 5: start the ultraviolet light source 2, and pre-illuminate the Si sheet for three minutes to further remove SiO ₂ remaining on the surface of the Si substrate sheet;

Step 6: Start the temperature controller of the photochemical vapor deposition equipment, set the substrate temperature to 450°C, and heat to the set temperature; turn on the heating power of the mercury chamber, and heat the mercury chamber to 50°C;

Step 7: Turn on the mass flow microcontroller of the photochemical vapor deposition equipment, set the flow rate of silane to 60SCCM, and set the flow rate of germane to 4SCCM; pump the gas pipeline through the vacuum system 5 for one minute to remove the residue in the gas pipeline Gas; then set the flow microcontroller in the running state;

Step 8: Open the outlet valve of reaction chamber 1, open the inlet valve of reaction chamber 1, input the reaction gas into reaction chamber 1, and maintain the pressure of reaction chamber 1 at 6Pa;

Step 9: Turn on the ultraviolet light source 2, and the material begins to grow epitaxially;

Step 10: After the ultraviolet light source 2 is irradiated for 10 minutes, turn off the ultraviolet light source 2, the reaction gas, the substrate temperature controller and the mercury chamber heating power supply in sequence;

Step 11: When the pressure of the reaction chamber 1 drops to 4Pa, start the molecular pump of the vacuum system 5, pump the vacuum degree of the reaction chamber 1 to 10 ^-5 Pa, and balance it with the preparation chamber 4; after that, use vacuum magnetic force to transfer The rod moves the silicon substrate from the reaction chamber 1 to the preparation chamber 4;

Step 12: Fill the processing chamber 3 and the preparation chamber 4 with high-purity nitrogen gas to an atmospheric pressure at the same time, send the silicon substrate to the processing chamber 3, and finally take out the silicon substrate from the processing chamber 3.

Example 2 is continuous growth of multilayer Si _1-x Ge _x /Si structure material (n-Si/i-Si _1-x Ge _x /p-Si _1-x Ge _x /i-Si _{1- x} Ge _x /n-Si/n ⁺ -Si), the layer structure of this material is shown in Figure 3, and its growth process is carried out according to the following steps:

Step 1: Same as Steps 1 to 6 in Example 1, except that the vacuum degree of the reaction chamber in Step 4 is changed to 8×10 ^-8 Pa, and the substrate temperature in Step 6 is changed to 400°C;

Step 2: Turn on the mass flow micro-controller of the photochemical vapor deposition equipment, set the flow rate of silane to 60 SCCM, set the flow rate of dichlorodihydrosilane to 20 SCCM, and set the flow rate of phosphine to 3 SCCM. Pump the air pipeline for one minute, and then set the flow micro-controller in the running state;

Step 3: Same as Steps 8 to 9 in Example 1, except that the pressure of reaction chamber 1 is maintained at 8Pa;

Step 4: After the ultraviolet light source 2 is irradiated for 25 minutes, cut off the ultraviolet light source 2 and the reaction gas to end the growth of the n-Si material;

Step 5: When the pressure of the reaction chamber 1 drops below 4Pa, start the molecular pump of the control system 5, and pump the vacuum of the reaction chamber 1 to 8×10 ^-8 Pa;

Step 6: Readjust the reaction gas flow rate of the mass flow microcontroller, set the flow rate of silane to 30SCCM, and set the flow rate of germane to 2SCCM; pump the gas pipeline for one minute, and then set the flow controller to the running state;

Step 7: Same as Step 8 to Step 9 of Example 1, except that the pressure of reaction chamber 1 is maintained at 3Pa;

Step 8: irradiating the ultraviolet light source 2 for 5 minutes, turning off the ultraviolet light source 2, cutting off the reaction gas, and ending the growth of the i-Si _1-x Ge _x material;

Step 9: Same as Step 5;

Step 10: Readjust the reaction gas flow of the mass flow micro-controller, set the flow of silane to 60SCCM, set the flow of germane to 4SCCM, and set the flow of borane to 3SCCM. Pump the air pipeline for one minute, and then set the flow micro-controller in the running state;

Step 11: Same as Step 8 to Step 9 of Example 1, except that the pressure of reaction chamber 1 is maintained at 6Pa;

Step 12: Same as Step 4, ending the growth of p-Si _1-x Ge _x material;

Step 13: Same as Step 5;

Step fourteen: the same as step six to step nine; end the growth of i-Si _1-x Ge _x material;

Step 15: Same as step 2 to step 4, except that the ultraviolet light source 2 is irradiated for 10 minutes to complete the growth of n-Si material;

Step sixteen: Turn on the mass flow micro-controller of the photochemical vapor deposition equipment, set the flow rate of silane to 60 SCCM, set the flow rate of dichlorodihydrogen silicon to 20 SCCM, and set the flow rate of phosphine to 9 SCCM. Pump the air pipeline for one minute, and then set the flow micro-controller in the running state;

Step seventeen: Same as steps three to four, except that the pressure of the reaction chamber 1 is maintained at 10 Pa, and the ultraviolet light source 2 is irradiated for 15 minutes to complete the growth of n ⁺ -Si material;

Step 18: Same as Step 10 to Step 12 in Example 1.

X-ray swing curve is the main characterization technique for the crystal quality of Si _1-x Ge _x /Si material. Fig. 4 shows the Si _{1-x Gex} /Si material (Example 1) epitaxially grown by the present invention, and the crystal structure analysis results were carried out by PHILIPS PW3040/00 X-Ray HRMRD in Xi'an Institute of Optics and Fine Mechanics, Chinese Academy of Sciences. The conclusion of the test report is: Si _1-x Ge _x /Si material is a single crystal with good crystallinity, and the sample is close to the level of foreign materials grown by UV/CVD technology.

The single-layer Si _1-x Ge _x /Si and multi-layer Si _1-x Ge _x /Si materials grown epitaxially by the present invention were analyzed by SIMS in the special material quality supervision and inspection center of the Ministry of Information Industry. Figure 5 and Figure 6 are the SIMS spectra of the single-layer Si _1-x Ge _x /Si material (Example 1) and the multi-layer Si _1-x Ge _x /Si material (Example 2) grown by this patent respectively. It can be seen from the figure that the Si _1-x Ge _x /Si material layer structure interface grown by the present invention is clear, the Ge composition and doping distribution are flat, and it has good interface characteristics and layer structure. The material of Example 2 of the present invention has been applied to the manufacture of Si/Si _1-x Ge _x /Si-HBT devices, and the electrical characteristics of the device show that the Si _1-x Ge _x /Si material applied to the epitaxial growth of the present invention has reached practical requirements.

Table 1 lists the growth process parameters of Examples 3 to 10 of the present invention.

Table 1 Gas Flow (SCCM) Substrate temperature (°C) Background pressure (Pa) Reaction pressure (Pa) Irradiation time (min) Silane Germane Borane Phosphine Dichlorodihydrosilane Example 3 (i-Si _1-x Ge _x /p-Si _1-y Ge _y ) layer 60 4 0 0 0 450 9× ^10-8 7 7 second floor 50 4 7 0 15 450 9× ^10-8 8 7 Example 4 (p-Si _1-x Ge _x ) 60 4 3 0 10 450 8.4×10 ^-8 6 5 Example 5 (i-Si _1-x Ge _x ) 50 2 0 0 0 450 1×10 ^-7 5 15 Example 6 (n-Si-p-SiGe/n-Si) layer 20 0 0 4 20 425 9.2×10 ^-8 2 10 second floor 60 2 3 0 10 425 6 20 three floors 20 0 0 4 20 425 2.5 10 Example 7 (n-Si _1-x Ge _x /i-Si _1-y Ge _y /i-Si/i-Si _1-x Ge _x /i-Si _1-y Ge _y ) layer 30 4 0 7 20 400 1×10 ^-7 6 20 second floor 30 2 0 0 10 400 4 10 three floors 20 0 0 0 20 400 3.6 5 four floors 30 2 0 0 10 400 4 10 five floors 30 4 0 0 20 400 5 20 Example 8 (p-Si _1-x Ge _x ) 20 0.5 1 0 5 450 8× ^10-8 2.5 30 Example 9 (i-Si _1-x Ge _x ) 80 3 0 0 20 400 9.5×10 ^-8 10 10 Example 10 (i-Si _1-x Ge _x ) 10 0.5 0 0 0 450 9.4×10 ^-8 1 50

After testing and analyzing the material samples of Examples 3 to 10, these materials all have single crystal characteristics and good interface characteristics and layer structures, and some materials have been applied to semiconductor devices. For example, the material structure in Example 7 is used to manufacture P-type heterojunction field effect transistors, and the devices have good electrical properties after testing. In addition, a national key project has been completed by applying the invention.

Claims (8)

1. a method of utilizing chemical vapor deposition techniques epitaxial growth SiGe/silicon is characterized in that, at silicon substrate film or the processing step and the condition that have on the silicon epitaxy layer substrate slice growth individual layer SiGe/silicon materials is:

A. place background vacuum pressure to reach 8 * 10-8～1 * 10 described substrate slice ^-7In the vacuum reaction chamber of Pa;

B. the temperature of vacuum reaction chamber is heated in 400～450 ℃ the scope;

C. feed reacting gas to described vacuum reaction chamber, reacting gas comprises silane (SiH ₄), germane (GeH ₄), flow rate of reactive gas is provided with according to doping content and the chemical reaction velocity that institute's growth material requires;

D. use the reacting gas in the described vacuum reaction chamber of ultraviolet source irradiation, its irradiation time is decided according to the thickness of institute's growth material, and during described ultraviolet source irradiation, the pressure of described vacuum reaction chamber maintains 1～10Pa all the time.

2. the method for epitaxial growth SiGe/silicon according to claim 1 is characterized in that, the N layer SiGe/Si material of can also growing, and its processing step and condition are:

E. when the growth of described individual layer SiGe/silicon materials finishes, close described ultraviolet source and stop to feed described reacting gas, the residual gas that will be trapped in the described vacuum reaction chamber pumps rapidly;

F. repeat processing step and the condition of b～d, growth is one deck SiGe/Si material down;

G. again processing step and the condition of e, f repeated N-2 time in turn.

3. the method for epitaxial growth SiGe/silicon according to claim 2 is characterized in that, also can grow N layer SiGe/Si heterojunction material, and its processing step and condition are:

H. in the process of growth N layer SiGe/Si material, germane flow set in the time of the individual material layer of N ' below the N layer SiGe/Si material can being grown is zero, and N '≤N-1, and the individual material layer of described N ' can be continuous, also can be discontinuous, or continuous and discontinuous coexistence.

4. according to the method for claim 1,2,3 described epitaxial growth SiGe/silicon, it is characterized in that: the reacting gas that feeds in described vacuum reaction chamber also comprises dichloro-dihydro silicon (SiH ₂Cl ₂).

5. according to the method for claim 1,2,3 described epitaxial growth SiGe/silicon, it is characterized in that: the reacting gas that feeds in described vacuum reaction chamber also comprises phosphine (PH ₃).

6. according to the method for claim 1,2,3 described epitaxial growth SiGe/silicon, it is characterized in that: the reacting gas that feeds in described vacuum reaction chamber also comprises borine (B ₂H ₆).

7. the method for epitaxial growth SiGe/silicon according to claim 5 is characterized in that: the reacting gas that feeds in described vacuum reaction chamber also comprises dichloro-dihydro silicon (SiH ₂Cl ₂).

8. the method for epitaxial growth SiGe/silicon according to claim 6 is characterized in that: the reacting gas that feeds in described vacuum reaction chamber also comprises dichloro-dihydro silicon (SiH ₂Cl ₂).

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