KR20090011765A - Method of depositing silicon oxide layer with increased gap-fill ability - Google Patents

Abstract

A method for depositing a silicon oxide layer is provided to deposit a mobility improved silicon oxide layer so as to form a film for a trench uniformly, and adjust the mixture ratio of silicon sources to control mobility of the silicon oxide layer. A method for depositing a silicon oxide layer comprises the following steps. At least one silicon source and a reaction gas are supplied into a reactor. A silicon oxide layer is deposited using the supplied silicon source and the reaction gas. The silicon oxide layer includes at least one bond among Si-H, Si-Cl, and Si-F bond in Si-O bond network. The Si-H, Si-Cl, and Si-F bond are provided from the silicon source.

Description

Method of depositing silicon oxide layer with increased gap-fill ability}

The present invention relates to a method for depositing an insulating film, and more particularly, to a method for depositing a silicon oxide film having improved gap-fill capability of a semiconductor device.

As the integration density of semiconductor devices such as DRAM is rapidly increasing, the operation speed of the semiconductor devices is required to increase, and the low power characteristics of the current semiconductor devices are also greatly increased. In order to meet these demands, the size of semiconductor devices must be continuously reduced.

As the size of a semiconductor device decreases, device characteristics must also be improved, but physical process limitations cause many problems. In particular, in the current shallow trench isolation (STI) process, as the aspect ratio of the trench increases as the size of the device decreases, the gap-fill ability of the insulating layer, or in other words, the problem of reducing the filling of the trenches, is emerging. The void due to lack of margin is increasing. Such voids cause problems such as a gate bridge. This gap-filling capacity reduction is also a problem in the intermetal dielectric (IMD) process, which requires filling gaps between metal wires in addition to the STI process.

Conventionally, high aspect ratio trenches and valley filling methods include HDP (High Density Plasma) -CVD (chemical vapor deposition), SA (Sub-Atmospheric) -CVD, and SOG (Spin On Glass).

Among them, HDP-CVD is a gap-fill method by repeating the deposition and etching of the silicon oxide film using a gas such as silane (silane, SiH ₄ ). This method is used by many device manufacturers because of its high productivity. However, high gap-fill capability requires low deposition rates and high etch rates. As a result, the lower layer may be etched or damaged, and even if the process conditions are configured with a wide allowable range, the lower layer may be etched due to a change in reactor state during mass production.

SA-CVD is the reaction by vaporizing a liquid such as tetra ethyl ortho silicate (TEOS), typically using the O ₃ -TEOS reaction. Since this method is a thermal CVD method, there is no problem of substrate damage that occurs when plasma is used, and there is an advantage of using O ₃ and TEOS which are widely used in semiconductor device manufacturing processes. However, in the gap-fill method by SA-CVD, in order to improve void quality and to improve film quality, high process temperature of 500 ° C. or higher and high process pressure of 600 torr or higher should be used. Because of this, the deposition rate is significantly reduced, there is a disadvantage that the by-products increase in the reactor and the component life in the reactor is shortened.

In addition, in a giga DRAM device having a trench depth of about 0.25 μm and a width of 0.1 μm or less, voids may be formed in the trench even if an HDP-CVD silicon oxide film or an SA ₃ CVD O ₃ -TEOS silicon oxide film is used. It is reported to be high.

In the SOG method, a polysilazane-based liquid material is dissolved in an organic solvent and applied by a spin coat method, and then the coated polysilazane coating film is applied in a water vapor (H ₂ O) or oxygen (0 ₂ ) atmosphere. Heat treatment. Polysilazanes include Si—N bond groups, Si—H bond groups and NH bond groups in the basic backbone. A silicon oxide film can be formed by volatilizing some components in a polysilazane coating film by heat processing in a steam or oxygen atmosphere, and converting a Si-N bond or a Si-H bond into a Si-O bond.

The SOG method has a feature of forming a silicon oxide film at a high versatility and at a low cost. However, a large amount of Si-N bond groups and Si-H bond groups remain in the silicon oxide film formed by the SOG method. For this reason, the electrical characteristics of the silicon oxide film formed by the SOG method, in particular, the dielectric breakdown voltage are lower than those of the HDP-CVD silicon oxide film and the SA-CVD type O ₃ -TEOS silicon oxide film, and the leakage current is high. Therefore, in the silicon oxide film formation method using SOG, there is high interest in the method of converting all Si-N couplers or Si-H couplers into Si-O couplers as much as possible.

In addition, due to the nature of the spin coat, the wide openings are only partially filled, and the film applied to the narrow trench becomes thicker than the film applied to the wide trench. In addition, there is a problem that the density of the membrane is very low. Moreover, in the case of narrow trenches, gas is trapped because volatilization at the lower part does not occur well, and thus there is a difference in density of the membrane in the trench depth direction. There is a problem that the etching rate for HF etching and the like are different. Furthermore, outgassing becomes a problem because the silicon oxide film formed by the SOG method is based on CH, OH, H, and the like. That is, the silicon oxide film formed by the SOG method has a Si-OH bond, and when sufficient outgassing is not performed, the silicon oxide film reacts with O _{2 in the} atmosphere to cause the H ₂ O component. The hygroscopicity of the SOG acts as a factor that inhibits the filling of vias by evaporation of some moisture absorbed in the via filling process in the via filling process when the vertical wiring connecting the lower and upper metal wirings is formed.

The problem to be solved by the present invention is to provide a silicon oxide film deposition method with improved gap-fill capability.

In one aspect of the silicon oxide film deposition method according to the present invention for solving the above problems, the silicon oxide film is deposited by supplying at least one silicon source and a reaction gas causing decomposition of the silicon source to the silicon oxide film, And depositing a silicon oxide film in a form in which at least one of Si—H, Si—Cl, and Si—F bonds is partially added to the O bond network.

At this time, the Si-H, Si-Cl and Si-F bonds are provided from the silicon source.

Preferably, the silicon source is a mixture of a tetra ethyl ortho silicate (TEOS) and a silicon compound containing at least one of the Si-H, Si-Cl and Si-F bonds in the molecular formula. At this time, by adjusting the flow rate of the TEOS, the silicon compound and the reaction gas, by adjusting the ratio of the Si-O bond and the Si-H, Si-Cl and Si-F bond, the film quality and fluidity of the silicon oxide film ( flowability) can be controlled.

If the existing SOG method was a method of applying a polysilazane material by spin coating and converting all of the Si-N or Si-H bonds of the applied polysilazane material to a Si-O bond as much as possible, the present invention The deposition method using a silicon source and a reaction gas partially adds at least one of Si-H, Si-Cl, and Si-F bonds to the Si-O bond network, and thus the method is completely different. In addition, the existing SOG method is a problem that the fluidity is too good and the film density is low, in the case of the present invention basically uses a high-density film deposition method, by adjusting the type and ratio of the silicon source and the film density and fluidity Any number of coordination is possible.

Another configuration of the silicon oxide film deposition method according to the present invention for solving the above problems is a silicon source comprising a silicon compound containing one to three Si-H bonds in the molecule and the reaction gas causing decomposition of the silicon source It is characterized in that the silicon oxide film is deposited by supplying to the reactor.

The reaction gas may be any one selected from the group consisting of O ₃ , H ₂ O ₂ , H ₂ O and a combination thereof. The deposition of the silicon oxide film may be any one of chemical vapor deposition (CVD), atomic layer deposition (ALD), cyclic CVD, and a combination thereof. At this time, the process temperature is 200 to 600 ℃, the process pressure may be 1 to 760 Torr. The silicon source further includes TEOS, and the silicon compound and TEOS may be supplied simultaneously or sequentially.

The silicon source may be transported and supplied as a carrier gas, which is any one of N ₂ , He, and Ar, or a combination thereof, and annealing in an H ₂ O, N _2, or O ₂ atmosphere after deposition of the silicon oxide layer. It may further include.

According to the present invention, by depositing a silicon oxide film in a form in which at least one of Si-H, Si-Cl and Si-F bond is partially added to the Si-O bond network of the silicon oxide film, a silicon oxide film having proper fluidity is deposited. can do. Here is that liquidity is adequate, good liquidity, rather than almost no liquidity as conventional HDP-CVD silicon oxide film, SA-CVD method on the silicon oxide layer O ₃ -TEOS gap-free means that Phil and SOG silicon in conventional manner Rather than having a very high fluidity, such as an oxide film, the fluidity is not so small that it does not partially fill a wide opening, and the thickness of the narrow trench and the wide trench does not change.

Such silicon oxide films are very useful for gap-filling high aspect ratio trenches.

In addition, according to the present invention, it is possible to deposit a stable silicon oxide film having a high deposition rate with a high gap-fill capability. The silicon oxide film deposition method according to the present invention can be used for deposition of various insulating films in a semiconductor process, for example, an insulating film (pre-metal layer) or an inter-metal insulating film (Inter Metal Dielectric, IMD) before forming the STI process metal wiring. Film) deposition, or capping film deposition to deposit for node separation after OCS (One Cylinder Storage) formation in DRAM.

In addition, the present invention can adjust the type and ratio of the silicon source, etc., it is possible to tune between the film quality (the density of the film is representative) and the fluidity. Therefore, the STI process that needs to increase the film quality to reduce the leakage current and improve the dielectric breakdown voltage can be coped with by lowering the Si-H, Si-Cl, and Si-F bond ratios to the Si-O bond. Even at the expense of some internal pressure, the capping film in the OCS process, in which the void-free gap-fill is the first priority with good fluidity, can be responded by increasing the Si-H, Si-Cl, and Si-F bond ratios to the Si-O bonds. have.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, embodiments of the present invention may be modified in many different forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art. Accordingly, the shape of the elements in the drawings and the like are exaggerated to emphasize a clearer description.

First embodiment

1 is a schematic diagram of a thin film deposition apparatus suitable for carrying out the silicon oxide film deposition method according to the present invention.

Referring to FIG. 1, the thin film deposition apparatus 1 is made of quartz, metal, or the like, and has a reactor 2 having an internal space, and a wafer 10 is disposed to be elevated in an internal space of the reactor 2. And a shower head 4 for injecting a silicon source as a raw material and a reaction gas into the reactor 2 so that a thin film is formed on the wafer block 3 to be heated by heating the wafer block 3 and the wafer 10 disposed on the wafer block 3. Equipped. The gas supply unit 7 supplies a gas or purge gas for adjusting the pressure in the reactor 2.

The thin film deposition apparatus 1 is for depositing an insulating film on a wafer 10 such as a silicon wafer for semiconductor or a glass substrate for LCD and the like, and a silicon source to the reactor 2 through gas lines 5a, 5b, and 5c. And gas supply devices 6a, 6b, 6c for supplying the reaction gas with each other. In this embodiment, an example in which two kinds of silicon sources and one kind of reaction gas are used and a gas line is also separately separated for the separation of these silicon sources and the reaction gas is given. If necessary, other types of silicon sources may be further supplied, and two or more kinds of silicon sources may be mixed in advance and supplied to the showerhead.

The method of depositing a silicon oxide film according to the present invention using the thin film deposition apparatus 1 is as follows.

First, the wafer 10 is loaded onto the wafer block 3 of the thin film deposition apparatus 1, and then two kinds of gas are supplied through the gas supply devices 6a, 6b and 6c and the gas lines 5a, 5b and 5c. A silicon source and a reaction gas are supplied to the reactor 2 to deposit a silicon oxide film on the wafer 10.

The silicon source may be a silicon compound having any one of the following structural formulas 1 to 3, wherein R, R ', and R "are each H, NH ₂ , N (C _n H _{2n + 1} ) ₂ , O (C _n H _{2n + 1} ), OSiC _n H _{2n + 3} or CnH _{n + 1} , n is 0 and a natural number, such a silicon compound may be Si-H, Si-Cl, or Si-O in the Si-O basic network structure of the silicon oxide film. It provides a Si-F bond, which is an essential silicon source for the deposition of the silicon oxide film according to the present invention.

[Formula 1]

[Formula 2]

[Formula 3]

When a silicon compound providing Si-H bond is used as a silicon source, the composition of the deposited silicon oxide film is SiOH, and the intermediate product is easily polymerized at the time of film formation, and thus has fluidity. When using a silicon compound that provides a Si-Cl bond as a silicon source, the composition of the deposited silicon oxide film is SiOCl, and when the film is formed, the intermediate is easily polymerized and has fluidity. On the other hand, the silicone compound (which is any one of R, R 'and R "while having the structural formula 2 above, which may be called a chlorohydrosilane derivative, has H-Cl bond as well as Si-Cl bond in the skeleton).

Preferred silicone compounds providing Si-F bonds may be fluorotriethoxysilane (SiF (OC ₂ H ₅ ) ₃ ). When the silicon compound providing the Si-F bond is used as the silicon source, the composition of the deposited silicon oxide film is SiOF, and the intermediate product is easily polymerized when the film is formed, thereby having fluidity. In addition, since the Si-F bond has a low binding energy, only the Si-F bond can be easily separated, and fluorine can be stably introduced into the SiOF film without incorporation of reaction byproducts into the SiOF film. Therefore, it is possible to deposit a silicon oxide film having low dielectric constant and hygroscopicity and excellent step-coverage.

In addition to these silicon compounds, TEOS can be further supplied as a silicon source. TEOS is a silicon source capable of depositing a silicon oxide film at a high deposition rate, and a silicon oxide film deposited using TEOS has a high density. Below, the structure of TEOS is represented by Structural Formula 4.

[Structure 4]

Thus, for example, the first silicon source TEOS is supplied through the gas supply device 6a and the gas line 5a, and the second silicon is supplied through the gas supply device 6b and the gas line 5b. The silicon compound of formula 1 as a source may be supplied. In particular, the silicon compound is preferably a silicon compound containing one to three Si—H bonds in the molecule. Especially, it is preferable that it is tetraethyl silanediamine which has a following structural formula (5).

[Structure 5]

The reaction gas causes decomposition of the silicon source to deposit a silicon oxide film, and for example, may be any one selected from the group consisting of O ₃ , H ₂ O ₂ , H ₂ 0, and a combination thereof.

The silicon source and the reactant gas may be transported and supplied by a carrier gas such as Ar. The carrier gas may be made of N ₂ or He, or a combination thereof in addition to Ar. The deposition of the silicon oxide film in the present invention may be any one of chemical vapor deposition (CVD), atomic layer deposition (ALD), cyclic CVD, and combinations thereof. At this time, the process temperature is 200 to 600 ℃, the process pressure may be 1 to 760 Torr.

The silicon source, silicon compound, and TEOS can be supplied simultaneously or sequentially. In the case of simultaneously supplying the silicon compound and TEOS, a uniform silicon oxide film is deposited in a form in which Si-H bond is partially added to the Si-O bond network of the silicon oxide film. In the case of sequentially supplying a silicon compound and TEOS, a laminated film structure of a silicon oxide film in which a Si-H bond is partially added to a silicon oxide film mainly based on a Si-O bond network of a silicon oxide film and a Si-O bond network of a silicon oxide film. The silicon oxide film is then deposited.

When the silicon source having any one of the structural formulas 1 to 3 is formed and supplied as the silicon source, the deposited silicon oxide film is formed of at least one of Si-H, Si-Cl, and Si-F bonds in the Si-O bond network. It becomes the form which added one partially. Of course, Si-H, Si-Cl and Si-F bonds are provided from silicon compounds having any one of formulas 1-3. As a result of the experiments of the present inventors, such a silicon oxide film has good fluidity and it is possible to gap-fill voids even in a high aspect ratio trench.

In particular, by controlling the flow rate of the TEOS, the silicon compound and the reaction gas, it is possible to appropriately control the film quality and fluidity of the silicon oxide film by adjusting the ratio of the Si-O bond and the Si-H, Si-Cl and Si-F bonds. . The higher the Si-O bond ratio, the lower the fluidity of the silicon oxide film, but the higher the density, the better the film quality. On the contrary, the relatively low ratio of Si-O bond increases the fluidity of the silicon oxide film, which is advantageous for the gap-fill. In this case, however, there is a problem that the density of the film is lowered, but this can be compensated by a subsequent annealing process. Preferred annealing is annealing in an H ₂ O, N ₂ or O ₂ atmosphere.

Second embodiment

2 is a gas flow diagram of a silicon oxide film deposition method according to an embodiment of the present invention, Figure 3 is a cross-sectional view according to the process.

First, before the deposition, the inside of the reactor 2 is maintained under vacuum pressure, and the wafer 10 for depositing the silicon oxide film is loaded onto the wafer block 3. Then, the temperature of the wafer 10 is maintained to an extent suitable for deposition of the silicon oxide film. This should be determined according to the type of silicon source and reactant gas. The temperature increase of the wafer 10 is achieved through a heater included in the wafer block 3, and the temperature of the wafer 10 is preferably 200 to 600 ° C., and further, 400 to 600 ° C. is maintained.

Then, the pressure inside the reactor 2 is increased to an extent suitable for the deposition of the silicon oxide film. The increase in pressure inside the reactor 2 is achieved through the gas supply 7, wherein the gas supplied may be a diluent gas which is not reactive, in particular Ar, He, N ₂ or a combination thereof. It is preferable to supply a gas so that the pressure inside the reactor 2 is about 1 to 760 Torr, further, about 10 to 200 Torr.

Then, a silicon source TEOS, tetraethyl silandiamine, and reaction gas O ₃ are supplied into the reactor 2 through the shower head 4 along the gas flow diagram shown in FIG. As described above, a silicon oxide film 40 is deposited on the wafer 10.

Referring to FIG. 2, TEOS, the first silicon source, is continuously supplied to the reactor 2. Here, "on" means the valve open state of the gas line 5a.

The second silicon source, tetraethyl silandiamine, is fed to reactor 2 for t1. Here, "on" indicates the valve open state of the gas line 5b, and "off" indicates the valve closed state of the gas line 5b. Then, tetraethyl silandiamine is purged for t 2. Here, "on" refers to the valve open state of the gas supply part 7, and "off" refers to the valve closed state of the gas supply part 7. When purging the inside of the reactor 2, a diluent gas used for pressure control is used. Through such supply and purge, one atomic layer of tetraethyl silandiamine is chemically adsorbed on the wafer 10. On the other hand, TEOS is hardly adsorbed on the wafer 10.

Then, the reaction gas O ₃ is supplied to the reactor 2 for t ₃ . Here, "on" indicates the valve open state of the gas line 5c, and "off" indicates the valve closed state of the gas line 5c. When O ₃ is supplied, a reaction between tetraethyl silandiamine, which is chemically adsorbed on the wafer 10, and O ₃ occurs, and the silicon oxide film 20 in which Si-H bond is partially added to the Si-O bond network of the silicon oxide film 20 ) Is first deposited on the wafer 10 in an ALD fashion as shown in FIG. 3. At the same time, TEOS supplied continuously and O ₃ react to form a silicon oxide film 30 mainly on the Si-O bond network of the silicon oxide film in a CVD method, strictly a cyclic CVD method. Then purge O ₃ for t4. This purge serves to remove by-products and unreacted O ₃ from the reaction.

Up to this point, i.e., steps t1 to t4 constitute one cycle, and the Si-H bond is partially added to the Si-O bond network of the silicon oxide film as the cycle is repeated until a predetermined film thickness is obtained. A laminate film of a silicon oxide film 20 of one type and a silicon oxide film 30 mainly based on a Si-O bonding network of the silicon oxide film, a so-called laminate structure silicon oxide film 40, is deposited. The silicon oxide film 20 in which the Si-H bond is partially added to the Si-O bond network of the silicon oxide film has excellent fluidity and excellent step coverage, and also has a high aspect ratio gap-filling ability. Do.

Further, by adjusting process variables such as the advancing time, TEOS supply amount, tetraethyl silandiamine supply amount, O ₃ supply amount, process temperature and process pressure in each section from t1 to t4, each silicon oxide film in the silicon oxide film 40 is controlled. It is possible to adjust the ratio and the deposition thickness of (20, 30), which results in the control of the fluidity and film quality of the silicon oxide film 40.

On the other hand, Figure 2 shows the gas pulsing (on, off) on a relative scale for the time comparison between t1 to t4, but is not necessarily limited thereto. 3 illustrates a cross section in which the silicon oxide film 40 is deposited on a flat portion of a portion of the wafer 10, this may be a part of a trench or a valley.

In this example, TEOS is supplied with only tetraethyl silandiamine and O ₃ in a pulse form (repetition of on and off) while continuously supplying. Although it corresponds to an example, it was explained that the silicon oxide film 40 having a laminated film structure can be obtained according to the difference in adsorption properties of TEOS and tetraethyl silandiamine.

Third embodiment

4 is a gas flow diagram of a silicon oxide film deposition method according to another embodiment of the present invention, the process cross-sectional view at this time is the same as FIG.

The procedure up to the supply of the silicon source and the reaction gas is the same as in the previous embodiment. In the present embodiment, a silicon source TEOS, tetraethyl silandiamine, and reaction gas O ₃ are supplied into the reactor 2 through the shower head 4 along the gas flow diagram shown in FIG. 4.

Tetraethyl silandiadiamine is first fed to reactor 2 for t1. Then, tetraethyl silandiamine is purged for t 2. Through such supply and purge, one atomic layer of tetraethyl silandiamine is chemically adsorbed on the wafer 10.

Then, the reaction gas O ₃ is supplied to the reactor 2 for t ₃ . When O ₃ is supplied, a reaction between tetraethyl silandiamine, which is chemically adsorbed on the wafer 10, and O ₃ occurs to partially add Si-H bonds to the Si-O bond network of the silicon oxide film. ) Is first deposited on the wafer 10 in an ALD fashion as shown in FIG. 3. Then purge O ₃ for t4. This purge serves to remove by-products and unreacted O ₃ from the reaction.

Next, in the section t5 TEOS and O ₃ are simultaneously supplied to the reactor (2). TEOS and O ₃ react to form a Si-H bond in a Si-O bond network of a silicon oxide film by a silicon oxide film 30 mainly oriented in a Si-O bond network of a silicon oxide film in a CVD method, strictly a cyclic CVD method. It is formed on the silicon oxide film 20 of the added form. Then purge O ₃ for t6. This purge serves to remove by-products and unreacted TEOS and O ₃ from the reaction.

Up to this point, that is, the steps t1 to t6 constitute one cycle, and as the cycle is repeated, the Si-H bond is partially added to the Si-O bond network of the silicon oxide film as shown in FIG. 3. A silicon oxide film 40 having a laminated film structure of a silicon oxide film 20 and a silicon oxide film 30 mainly on the Si-O bonding network of the silicon oxide film is deposited.

In the present embodiment, the TEOS and tetraethyl silandiamine are sequentially supplied, and it has been described that the silicon oxide film 40 having the laminated film structure can be obtained by this method.

Fourth embodiment

5 is a gas flow diagram of a silicon oxide film deposition method according to another embodiment of the present invention, Figure 6 is a cross-sectional view according to the process.

The process up until the supply of the silicon source and the reaction gas was carried out in the same manner as in the previous embodiments, followed by the silicon source TEOS, tetraethyl silandiamine, and the reaction gas O according to the gas flow diagram shown in FIG. 5. ₃ is fed into the reactor 2 through the showerhead 4.

Tetraethyl silandiamine is fed continuously to the reactor (2). TEOS and O ₃ are fed to reactor 2 for t1. Then stop TEOS and O ₃ supply for t2. Although TEOS and O ₃ are supplied in a pulsed form, tetraethyl silandiamine, TEOS, and O ₃ are supplied simultaneously to deposit by cyclic CVD. A purge may be performed during t2 to stop TEOS and O ₃ supply.

So far, i.e., the steps t1 to t2 constitute one cycle, and as the cycle is repeated, as shown in FIG. 6, the Si-H bond is partially added to the Si-O bond network of the silicon oxide film. In one form, a uniform silicon oxide film 40 'is deposited on the wafer 10.

In the present embodiment, the TEOS and tetraethyl silandiamine are supplied at the same time, and it was explained that a uniform silicon oxide film 40 'can be obtained by this method.

Fifth Embodiment

7 is a gas flow diagram of a silicon oxide film deposition method according to another embodiment of the present invention, the process cross-sectional view at that time is the same as FIG.

The process up to the supply of the silicon source and the reaction gas was carried out in the same manner as in the previous embodiments, and then, according to the gas flow diagram shown in FIG. 7, the silicon source TEOS, tetraethyl silandiamine, and reaction gas O ₃ is fed into the reactor 2 through the showerhead 4.

O ₃ is continuously fed to the reactor 2. TEOS and tetraethyl silandiamine are fed to reactor 2 for t1. Then, the TEOS and tetraethyl silandiadiamine feed is stopped for t2. TEOS and tetraethyl silandiamine are supplied simultaneously to deposit by cyclic CVD. Purge may be performed during t2 to stop TEOS and tetraethyl silandiamine feed.

So far, i.e., the steps t1 to t2 constitute one cycle, and as the cycle is repeated, as shown in FIG. 6, the Si-H bond is partially added to the Si-O bond network of the silicon oxide film. In one form, a uniform silicon oxide film 40 'is deposited on the wafer 10.

In this embodiment, the TEOS and tetraethyl silandiamine were simultaneously supplied, and it was explained that a uniform silicon oxide film 40 'could be obtained by this method.

Sixth embodiment

8 is a gas flow diagram of a silicon oxide film deposition method according to another embodiment of the present invention, the process cross-sectional view at that time is the same as FIG.

The process up until the supply of the silicon source and the reaction gas was carried out in the same manner as in the previous embodiments, followed by the silicon source TEOS, tetraethyl silandiamine, and the reaction gas O according to the gas flow diagram shown in FIG. 8. ₃ is fed into the reactor 2 through the showerhead 4.

O ₃ is continuously fed to the reactor 2. Tetraethyl silandiadiamine is first fed to reactor 2 for t1. Reaction between tetraethyl silandiamine and O ₃ occurs so that the silicon oxide film 20 in which Si-H bond is partially added to the Si-O bond network of the silicon oxide film is cyclic on the wafer 10 as shown in FIG. 3. It is deposited by CVD method. The feed of tetraethyl silandiamine is then stopped and TEOS is fed to reactor 2 for t2. The step of purging inside the reactor 2 may be further carried out before feeding TEOS while stopping the tetraethyl silandiamine feed. In the t2 section, TEOS reacts with O ₃ and forms a Si-H bond partially added to the Si-O bond network of the silicon oxide film by the silicon oxide film 30 mainly based on the Si-O bond network of the silicon oxide film by cyclic CVD. Is deposited on the silicon oxide film 20. Then, the feed of TEOS is stopped and again, tetraethyl silandiamine is fed to reactor 2 for t1. The step of purging inside the reactor 2 may be further carried out before feeding the tetraethyl silandiamine, while stopping the TEOS feed.

Steps t1 to t2 constitute one cycle, and as such a cycle is repeated, a silicon oxide film 40 having a laminated film structure can be obtained as shown in FIG.

Experimental Example

9 is a cross-sectional SEM photograph of a trench in which a conventional O ₃ -TEOS silicon oxide film is deposited. The trench top CD was 110nm and the bottom CD was 100nm.

In FIG. 9, the length of the open portion (the portion not filled with the membrane) was measured and displayed in the trench length direction. After about 30: 1, since the length of the open site is 99 nm, it can be confirmed that the deposition of the silicon oxide film is hardly performed. That is, it has a level | step difference applicability of the grade which is not applicable to the trench which has aspect ratio 30: 1 or more.

10 is a cross-sectional SEM photograph of a trench in which a silicon oxide film is deposited according to the present invention. In this case, the trench top CD was 110nm and the bottom CD was about 100nm. The silicon oxide film deposition method was according to the second embodiment, and the process temperature was 320 占 폚 and the process pressure was 8 Torr.

In FIG. 10, the length of the open portion was measured and displayed in the trench length direction. Since the open portion has a length of 46.4 nm until about 27: 1, it can be confirmed that the silicon oxide film is deposited to a certain uniform thickness up to this depth. Although no cross-sectional SEM photographs are attached, it is expected that a silicon oxide film would of course be deposited at depths beyond 27: 1. Although it is not completely gap-filled with the silicon oxide film to confirm the step applicability, as can be seen from the step applicability confirmation, the gap-fill can be proceeded without a void as a matter of course according to the second embodiment.

11 is another SEM image of a trench in which a silicon oxide film is deposited according to the present invention. (a) is a high magnification photograph showing the upper side of the trench and (b) is a whole photograph showing the trench bottom. In this case, the trench top CD was 110nm and the bottom CD was about 100nm. The silicon oxide film deposition method was according to the second embodiment, and the process temperature was 480 占 폚 and the process pressure was 8 Torr.

In FIG. 11, the length of the open portion was measured and displayed in the trench length direction. It can be seen that the silicon oxide film was deposited up to about 70: 1. This is a significant improvement over the result of FIG. 9 where no silicon oxide film is deposited after 30: 1. Although it is not completely gap-filled with the silicon oxide film to confirm the step applicability, as can be seen from the step applicability confirmation, it is expected that the gap-fill can be proceeded without a void without progressing according to the second embodiment. .

In the above, the present invention has been described in detail with reference to preferred embodiments, but the present invention is not limited to the above embodiments, and various modifications are possible by those skilled in the art within the technical idea of the present invention. Is obvious. Embodiments of the invention have been considered in all respects as illustrative and not restrictive, which include the scope of the invention as indicated by the appended claims rather than the detailed description therein, the equivalents of the claims and all modifications within the means. I want to.

1 is a schematic diagram of a thin film deposition apparatus suitable for carrying out the silicon oxide film deposition method according to the present invention.

2 is a gas flow diagram of a silicon oxide film deposition method according to an embodiment of the present invention.

3 is a cross-sectional view of the process according to FIG. 2.

4 is a gas flow diagram of a silicon oxide film deposition method according to another embodiment of the present invention.

5 is a gas flow diagram of a silicon oxide film deposition method according to another embodiment of the present invention.

6 is a cross-sectional view of the process according to FIG. 5.

7 is a gas flow diagram of a silicon oxide film deposition method according to another embodiment of the present invention.

8 is a gas flow diagram of a silicon oxide film deposition method according to another embodiment of the present invention.

9 is a cross-sectional SEM photograph of a trench in which a conventional O ₃ -TEOS silicon oxide film is deposited.

10 is a cross-sectional SEM photograph of a trench in which a silicon oxide film is deposited according to the present invention.

11 is another SEM image of a trench in which a silicon oxide film is deposited according to the present invention.

<Explanation of symbols for the main parts of the drawings>

1 ... thin film deposition apparatus 2 ... reactor

3 ... wafer block 4 ... shower head

5a, 5b, 5c ... gas line 6a, 6b, 6c ... gas supply

7.Gas Supply 10 ... Wafer

20, 30, 40, 40 '... silicon oxide

Claims (14)

At least one silicon source and a reaction gas causing decomposition of the silicon source are supplied into the reactor to deposit a silicon oxide film, A silicon oxide film deposition method comprising depositing a silicon oxide film in a form in which at least one of Si-H, Si-Cl, and Si-F bonds is partially added to a Si-O bond network of a silicon oxide film. The method of claim 1, wherein the Si—H, Si—Cl, and Si—F bonds are provided from the silicon source. The method of claim 1, wherein the silicon source is a mixture of a tetra ethyl ortho silicate (TEOS) and a silicon compound containing at least one of the Si-H, Si-Cl and Si-F bonds in a molecular formula is used. A silicon oxide film deposition method. 4. The silicon according to claim 3, wherein a ratio of the Si—O bond and the Si—H, Si—Cl, and Si—F bonds is controlled by adjusting a supply flow rate of the TEOS, the silicon compound, and the reaction gas. Oxide film deposition method. The method of claim 3, wherein the silicon compound has any one of the following structural formula, wherein R, R ', R "are each H, NH ₂ , N (C _n H _{2n + 1} ) ₂ , O (C _n H _{2n + 1} ), OSiC _n H _{2n + 3} , CnH _{n + 1} , and n is 0 and a natural number.

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A silicon oxide film deposition method comprising depositing a silicon oxide film by supplying a silicon source comprising a silicon compound containing 1 to 3 Si—H bonds in a molecule and a reaction gas causing decomposition of the silicon source into a reactor. 7. The method of claim 6 wherein the reactive gas is _{O 3, H 2 O 2,} H 2 0 and any one of a silicon oxide film deposition process, characterized in that selected from the group consisting of. The method of claim 6, wherein the silicon compound has the following structural formula, wherein R, R ', R "are each H, NH ₂ , N (C _n H _{2n + 1} ) ₂ , O (C _n H _{2n + 1} ) , OSiC _n H _{2n + 3} , CnH _{n + 1} , n is 0 and a natural number, characterized in that the silicon oxide film deposition method.

The method of claim 6, wherein the silicon compound is tetraethyl silanediamine having the following structural formula.

The method of claim 1, wherein the deposition is any one of chemical vapor deposition (CVD), atomic layer deposition (ALD), cyclic CVD, and combinations thereof. Silicon oxide film deposition method. The method of claim 10, wherein the process temperature is 200 to 600 ° C. and the process pressure is 1 to 760 Torr. The method of claim 6, wherein the silicon source further comprises TEOS, and the silicon compound and the TEOS are simultaneously or sequentially supplied. 7. The method of claim 1, 3, and 6, wherein the silicon source is delivered to the carrier gas which is any one selected from the group consisting of N ₂ , He, Ar, and combinations thereof. A silicon oxide film deposition method. The method of claim 1, further comprising annealing in an H ₂ O, N ₂ or O ₂ atmosphere after deposition of the silicon oxide film. .

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