JPH1072672A - Non-plasma type chamber cleaning method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for cleaning a process chamber of CVD or other types of not using gaseous PFC and a device therefor. SOLUTION: Molecular fluorine (F2 ) diluted with an inert carrier gas is introduced into a treating chamber to clean the chamber. One of embodiments is executed to heat at least a part of the chamber at >=400 deg.C, to introduce the diluted gaseous F2 into the chamber and to set the chamber pressure at 1 to 100Torr or a level above the range. At least a part of the chamber is heated to >=400 deg.C, by which the free fluorine having reactivity is formed from the dilute gaseous F2 and thermal reaction is effected between the dilute gaseous F2 and the deposits in the chamber. The deposits are removed by etching from the regions of the chamber or other regions where the undesired deposits are accumulated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for manufacturing an integrated circuit. More specifically, the present invention is a technique for removing the accumulation of particles and residues generated during substrate processing, including methods and apparatus. The present invention is particularly suitable for chemical vapor deposition, but is also applicable to plasma etching and other substrate processing techniques.

[0002]

2. Description of the Related Art At present, a basic step of manufacturing a semiconductor device includes a step of forming a thin film on a substrate by a chemical reaction of gas. This deposition process
It is called chemical vapor deposition or CVD. In a conventional thermal CVD process, a reactive gas is supplied to a substrate surface to cause a thermally excited chemical reaction to form a thin film layer on the surface of the substrate to be processed.

[0003] One of the characteristic uses of thermal CVD is tungsten hexafluoride and silane.
e) depositing a tungsten-containing compound such as tungsten or tungsten silicide on a semiconductor substrate from a process gas containing hydrogen and / or other gases. Such tungsten processes are often used in metal layer deposition processes or as part of a process for depositing a metal interconnect between a metal layer and a substrate or another metal layer. Can be

[0004] One of the problems encountered during tungsten, tungsten silicide, and other CVD processes is the formation of unwanted deposits on areas such as the walls of the process chamber. This unwanted deposit, unless removed,
It is a source of particulate contaminants that interfere with subsequent processing steps and adversely affect wafer yield.

[0005] To prevent this problem, the interior surface of the chamber is periodically cleaned to remove unwanted deposits from the chamber walls and similar areas of the processing chamber. This procedure is performed as a standard cleaning operation, where an etch gas such as NF ₃ is used to remove (etch) deposits from chamber walls and other areas.
Such a cleaning procedure is usually performed for each wafer deposition step or n wafer deposition steps.

[0006] Conventional etching techniques include plasma C
VD technology is included, which promotes the excitation and / or decomposition of the reaction gas by applying radio frequency (RF) energy to a reaction region adjacent to the substrate surface. In such a technique, highly reactive plasma species are generated, which react with unwanted deposits and etch away from chamber walls and other areas.

[0007]

Most of the fluorine gas used as an etchant gas in the plasma cleaning process in the semiconductor industry is a perfluoro compound (perfluoro compound).
fluorocompounds), or “PFC” for short.
Commonly used PFCs include CF ₄ , C ₂ F ₆ , NF ₃ , S
F ₆ and other gases are included. Such a gas is known to have a long life (for example, CF4 is 50,000 years or more), and is considered to have a high contribution to global warming. Thus, releasing PFCs into the atmosphere is damaging and subject to government and other regulations. Therefore, it is important to reduce the emission of PFC from a semiconductor processing device such as a CVD reactor.

[0008] Examples of non-PFC gases that have been employed as etchant gases in cleaning operations include molecular fluorine (F).
₂ ) and chlorine trifluoride (ClF ₃ ). For example,
When the hot-wall CVD reactor is heated to 100 to 400 ° C. to perform a thermal cleaning reaction, a cleaning gas that may be used includes F ₂ diluted to 20%. F ₂ is a highly volatile gas. However, when using the F ₂ at the level of such a high concentration, in order to maintain the level of proper safety, it is necessary to use a special device such as a double encompassed gas supply line.

[0009]

SUMMARY OF THE INVENTION The present invention provides a method for cleaning a CVD or other type of process chamber without PFC gas. In the method of the present invention, molecular fluorine (F ₂ ) diluted with an inert carrier gas is introduced into a processing chamber and the chamber is cleaned.

In one embodiment, the method comprises heating at least a portion of the chamber to a temperature of 400 ° C. or higher.
Dilute F ₂ gas is introduced into the chamber and the chamber pressure is reduced to 1
Set to a level of ~ 100 Torr or higher. By heating at least a portion of the chamber above 400 ° C., to produce free fluorine having reactive from dilute F ₂ gas, and causing thermal reaction between the sediment in the diluting F ₂ gas and the chamber Etch away the deposits from the chamber and other areas where unwanted deposits are accumulating. In a preferred aspect of this embodiment, the diluting F ₂ gas F ₂
Introduced at a concentration level of about 10% or less, and F
_A standard gas line is used to introduce the _two gases.

[0011] In another embodiment of the method of the present invention, at least a portion of the chamber is heated to a temperature of about 400-650 ° C and a pressure of at least about 1-100 Torr is provided. Next, a plasma is generated from the diluted F ₂ gas introduced into the chamber, and a substance deposited on an undesired area in the chamber is removed by etching. The energy required to generate reactive free fluorine in the plasma from the diluted F ₂ gas is smaller than the energy required to generate reactive free fluorine in the plasma from the PFC gas such as NF _3. .

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 and 2. Exemplary CVD Reactor FIGS. 1 and 2 illustrate a parallel plate cold wall chemical vapor deposition reactor 10 having a vacuum chamber 12 in which the present Layers can be deposited according to the invention. The reactor 10 includes a resistance heating susceptor 18.
It has a gas distribution manifold 14 for dispersing the deposit gas on the wafer 16 mounted thereon.

The chamber 12 may be part of a vacuum processing system having a number of processing chambers (multi-chambers), which are connected to a central transfer chamber and operated by a robot. The substrate 16 is carried into the chamber 12 by a robot blade via a slit valve (not shown) on the side of the chamber. The susceptor 18 is vertically movable by a motor 20. When the susceptor 18 is in the first position 17 opposite the slit valve, the substrate 16 has been carried into the chamber. In position 17, the substrate 16 is initially supported by a set of pins 22 that penetrate and couple to the susceptor 18. Pin 22 is driven by a single motor assembly.

When the susceptor is carried to the processing position 32 opposite the gas distribution manifold 14 as indicated by the dotted line, the pins 22 sink into the susceptor 18 and the substrate 16 is placed on the susceptor. . Once placed on the susceptor 18, the substrate 16 is secured to the susceptor by a vacuum clamping system (partially shown as groove 50 in FIG. 2).

When moving toward the processing position 32, the substrate 16 contacts the purge guide 54 and centers the purge guide 54 on a fixed substrate.
When the centering of the purge guide is performed, the purge guide is not in contact with the substrate 16, and a gap of 5 to 10 mil (1000 mil = 1 inch = about 25.4 mm) fixed as a passage for the purge gas is maintained between the purge guide and the substrate. Bumper pins 52 on the side walls 51 of the susceptor 18 help to minimize contact between the purge guide 54 and the susceptor 18 and cause particles to be generated as the 18 and the purge guide 54 contact each other as they pass. Is reduced.

The purge guide 54 is located on top of the susceptor 18 when the susceptor 18 is in the processing position 32. The deposition gas and the carrier gas are supplied to the valve 17.
Is supplied to the manifold 14 via the gas line 19 in accordance with the amount of adjustment. During processing, the gas supplied to the manifold 14 is evenly distributed from one end of the substrate surface to the other. Spent process and by-product gases are exhausted from the chamber by an exhaust system. Exhaust system 3
The flow rate of the gas released to the exhaust line via 6 is regulated by a throttle valve (not shown). During the deposition operation, a purge gas supply line 38 supplies a purge gas to the edge of the wafer 16. The purge guide is made of a ceramic such as aluminum oxide or aluminum nitride.

The edge of the susceptor, on which the purge guide 54 is placed during processing, has a plurality of fine edges (for example, an interval of 5 to 10 mi).
1) to prevent "sticking" between the purge guide 54 and the susceptor. This sticking creates particles, which occur because the expansion coefficients between the metal (susceptor), such as aluminum, and the ceramic (purge guide) portions are different. At the processing temperature, aluminum expands about three times as much as ceramic at room temperature. Therefore, when the substrate processing is completed and the susceptor is lowered and the purge guide 54 and the susceptor 18 are separated from each other, the generation of particles is prevented by the groove 56. Second
1 protects the stainless steel bellows 26 from damage by corrosive gases introduced into the chamber during processing. Plasma enhanced chemical vapor (PECVD) of the chamber
An RF power source 48 is connected to the manifold 14 to provide for deposition cleaning.

Throttle valve, gas supply valve 17, motor 2
0, resistive heater coupled to susceptor 18, RF power supply 48
And other features of the CVD system 10 are controlled by the processor 42 via control lines 44 (only some are shown). Processor 42 operates under the control of a computer program stored on a computer-readable medium such as memory 46. This computer program dictates the temperature, chamber pressure, timing, gas mix, RF power level, susceptor position and other parameters for a particular process.

Such a CVD apparatus is disclosed in US Pat. N. 08 / 042,961, Title "Improved Che
mical Vapor Deposition Chamber "(" Improved Chemical Vapor Deposition Chamber "). The above CVD
The description of the system is primarily for purposes of illustration and should not be considered as limiting the scope of the invention. Variations of the above-described system are possible, such as platen or wedge design, heater design, placement of RF power connections, and other variations. Furthermore, an inductively coupled plasma CVD apparatus, an electron cyclotron resonance (ECR).
A plasma CVD device, an etching device, or another device may be used. The method of the present invention for removing unwanted deposits is not limited to a particular processing apparatus.

2. Exemplary Chemical Vapor Deposition Process The method of the present invention can be used to clean the interior surfaces of an exemplary CVD reactor 10 or other reactor. The process for depositing a tungsten film on a substrate is illustrated below, as an example of a CVD operation that leaves unwanted deposits in the chamber 12 after the deposition process, and after the termination of the present invention, This is an example in which undesired deposits can be removed from the chamber wall using the method described above. Although the method of the present invention is particularly useful for removing unwanted tungsten and / or tungsten silicide residues, the following examples are for exemplary purposes only, and the method of the present invention is an exemplary process. It should be understood that the present invention is not limited to cleaning or removing sediments from the seawater.

In this exemplary process, a tungsten film is deposited on a wafer placed in the processing chamber 12. This deposition sequence mainly includes two steps: a nucleation step and a bulk deposition step. In the nucleation step, a thin layer of tungsten is grown, which acts as a growth site for subsequent films. In the nucleation step, tungsten hexafluoride (WF ₆ ), silane (SiH ₄ ), nitrogen (N ₂ ),
A process gas containing hydrogen (H ₂ ) and argon (Ar) is introduced into the chamber, and the chamber is heated and pressurized to a selected level to deposit an initial tungsten seed layer for the next deposition.

After the nucleation step, a bulk deposition step is performed to deposit the remaining tungsten film. In this bulk deposition step, a process gas containing WF ₆ , N ₂ , H ₂ and Ar is introduced into the chamber. This process gas has a higher percentage of WF ₆ than the process gas for the nucleation step. An edge purge gas may be used in both the nucleation step and the bulk deposition step to prevent deposition on the edge and backside of the wafer, as with the susceptor described in the exemplary chamber section. However, this purge gas does not prevent deposition on all unwanted areas in the chamber and therefore does not eliminate the need for a dry cleaning step.

In one preferred process, during the nucleation process, WF ₆ is introduced into the chamber at a flow rate of 20 sccm.
, SiH ₄ at a flow rate of 10 sccm, N ₂ at a flow rate of 300 sccm, and H ₂ at a flow rate of 1000 sccm.
cm, and Ar is introduced at 2800 sccm. Heat the wafer to 450 ° C. and maintain the pressure at 80 Torr. Then, during the bulk deposition process, WF ₆ was introduced into the chamber at a flow rate of 300 sccm, and N ₂ was introduced at a flow rate of 3 sccm.
H ₂ is introduced at a flow rate of 700 sccm, and Ar is introduced at a flow rate of 1000 sccm.

In this preferred process, the edge purge gas introduces only Ar at a flow rate of 200 sccm during the nucleation step, and introduces Ar at a flow rate of 1800 sccm and H ₂ at a flow rate of 330 sccm during the bulk deposition step. The addition of hydrogen to the purge gas is to promote deposition at the edge of the substrate.

(3. Chamber Cleaning)
While performing a deposition sequence, such as the exemplary tungsten process described above, it can be used to remove unwanted deposits that accumulate in the chamber 12. In the method of the present invention, molecular fluorine (F ₂ ) is diluted with an inert carrier gas and introduced into the chamber 12 as a dry cleaning step after deposition and other substrate processing steps. Possible carrier gases include N ₂ , A
r, neon (Ne) or helium (He) and other gases. The concentration of F ₂ is about 1 of the concentration of the carrier gas.
Dilute to ~ 20%. Preferably, the concentration of F ₂ is diluted to about 5-10% of the concentration of the carrier gas. At such low concentration levels, dilute F2 gas can be introduced via a single wall 316 stainless steel line, which can be matched to safety. If the concentration level is high, special care must be taken, such as using a double stainless steel line or Hastelloy line, to meet safety standards.

According to the technique of the present invention, the chamber cleaning may be performed by performing the deposition processing and the wafer processing operation on one wafer in the same chamber, or the processing may be performed every time n wafers are processed. The technology of the invention may be used.
FIG. 3 is a simplified flowchart of a series of operations on a wafer in one embodiment of the method of the present invention. To start this series of operations, load the substrate into the chamber,
Processing is performed according to the exemplary process described above or performed by other processing operations (step 30).
0). After the substrate processing operation is completed, the substrate is taken out of the chamber (Step 305), and the controller 42 determines whether or not to perform dry cleaning (Step 31).
0). Typically, n is 1-25. For processing operations that have a high risk of particle accumulation, such as the exemplary tungsten process described above, n is preferably 1.

In the cleaning step, at least a part of the chamber is heated to a temperature of 400 ° C. or higher (step 315), and dilute molecular fluorine is introduced into the chamber (step 320). The pressure in the chamber is about 1-10
The level is set at or above 0 Torr and is maintained (step 325). Both temperature and pressure affect the rate at which deposits are etched away during the cleaning step. An increase in temperature and / or pressure generally increases the etch rate (etch rate). In practice, the speed increase depends on the sediment.

It should be noted that it is not necessary to heat the entire chamber uniformly to perform the cleaning operation. In fact, uniform heating of the chamber does not occur in a cold wall reactor such as reactor 10.
Instead, a portion of the chamber is heated to a temperature of 400 ° C. or higher while the other portion of the chamber is maintained at a sufficiently low temperature. In such a case, the high temperature portions of the chamber (e.g., resistive heating platen, etc.), the when the F ₂ is flowed into the hot section or in the region near its being introduced into the chamber to activate the F ₂ It is possible.
This activated F ₂ has many reactive free fluorine atoms. In the vicinity of the source of the near or reactive free fluorine in this hot area, but the etch rate is increased, if so deposit is in contact with the activated F ₂ molecule, occurs etching action in the downstream from this region. In such a situation, this hot zone is referred to as the main or active zone.

It is also possible to have a dedicated heat activator, such as an induction coil or the like, arranged to contact the coil before the flow of F ₂ enters the chamber. The heat activator heats the substrate to 400 ° C. or higher to form a heat activated region. Then, F ₂ molecules activated, from the region at a lower temperature in the downstream of the chamber walls and other activators, remove the material by etching. In such a configuration, the coil (or other heat activator) should be designed to have a resistance to corrosive F ₂ gas.

In cleaning unwanted tungsten and tungsten silicide deposits, the chamber pressure is about 10-80 Torr and the chamber temperature is 425-55.
0 ° C. (in the main reaction zone) gives the favorable conditions and sufficient etch rate of a lamp heated MCVD chamber from Applied Materials. Higher temperatures and pressures may be used, which may be desirable in certain circumstances. For example, in cleaning polysilicon material deposits, temperatures as high as 700 ° C. or higher can be used because the temperature at which polysilicon is deposited is high.
As another example, a temperature of about 700 to 850 ° C. may be used for cleaning an undesired deposit of silicon, silicon oxide, or silicon nitride.

Even if the pressure is higher than 80 Torr, the advantage is limited to the advantage of etching a deposit deposited by a tungsten process or a tungsten silicide process (for example, the etch rate is increased). Also,
If the reactor is designed to be adapted to atmospheric or sub-atmospheric processing conditions, if the pressure is raised to about 700 to 760 Torr, the etch rate will still be higher for certain process chemical systems such as tungsten and tungsten silicide. It may be advantageous in the form of increase.

The operating time of the cleaning step depends on the amount of residue and particles accumulated in the chamber. Preferably, a cleaning step is selected so that substantially all of the particles and residues can be removed from within the chamber (step 330). The flow rate at which F ₂ is introduced is determined in consideration of the balance between gas cost and etching time. In general, this flow rate is approximately at F ₂ 25 to 1000
sccm. With this introduction flow of 25-1000 sccm, the total gas flow into the chamber at 125% dilution is 125
５5000 sccm. The actual flow rates of both F ₂ and inert gas, varies with chamber volume.

A high F ₂ introduction flow rate means a high cost, or a high etch rate per unit time. However, as shown in FIG. 4, when the introduction flow rate increases, the flow rate at which F ₂ is introduced reaches a saturation point at which the etch rate does not increase. Also, as exemplified by the slope of the curve in FIG.
Increasing the introduction flow rate of Step ₂ to near the saturation point has a diminishing return of the increase in etch rate. The slope of this curve represents the efficiency of etch rate versus gas cost. The actual flow rate should be chosen to balance cost and etch factors.

As mentioned above, the method of the present invention is not limited to removing material deposited in the chamber by the exemplary tungsten process described above. Rather, the present invention is equally applicable to cleaning materials from a tungsten CVD process using another precursor gas, such as tungsten hexachloride. Also,
The F ₂ chemistry of the present invention is applied to material cleaning in the deposition process of tungsten silicide, titanium nitride, silicon nitride, doped polysilicon, undoped polysilicon, doped silicon oxide, undoped silicon oxide and other compounds. You can also.

In some embodiments of the method of the present invention, the dilution F
₂ is sufficiently reactive under thermal conditions that plasma generation is not required for proper cleaning of the chamber. Such specific examples include, but are not limited to, deposits accumulated in applications of tungsten or tungsten silicide. Thus, devices designed for the deposition of thermal CVD films in accordance with tungsten, tungsten silicide, other metals, and other such embodiments, require the RF generator, RF matching circuit and other hardware necessary for plasma generation. No need. This allows significant cost savings for the reactor 10 and other parts.

In another embodiment, RF or microwaves are applied to generate a plasma to further clean the chamber. In this plasma, the energy required to generate reactive free fluorine is significantly reduced as compared with the energy required to generate reactive free fluorine from a PFC gas such as NF ₃ . While these examples still require an RF generator and other related hardware,
The use of dilute F ₂ cleaning gas, it is possible to lower the RF power in the operation of the chamber cleaning. The lower RF power used means that less energy is required than would be required if PFC gas were also used, thus reducing operating costs and reducing the rate of chamber wear. That's what it means. This also reduces the size of the RF generator that can generate the required power levels, saving space and cost. Thus, the use of low power plasma can increase the reaction rate more than twice, depending on the material to be etched, the power level used, and other factors. In addition, a remote microwave can be used to generate the necessary plasma.

The use of a diluted molecular fluorine cleaning gas provides additional advantages over other fluorine sources in addition to those described above. One is that F ₂ has a strong odor and can be sensed at a concentration 10 times lower than that of NF ₃ . Therefore, if there is leakage from the gas supply line of the F _2, it is likely to find earlier than leakage of other gases (and can be stopped prematurely). Further, although things in the United States, diluted F ₂ is spread distribution network in the United States throughout already routinely distributed for use in numerous applications other than the application.

[0039]

【Example】

5. Test Results and Measurements To illustrate the operation of the apparatus and method according to the present invention, measurements were made of the etch rate of tungsten silicide with respect to temperature. The experiment was performed in a 200 mm wafer lamp heated MCVD chamber manufactured by Applied Materials. The volume of the chamber is
It was 5 liters.

In the first set of these experiments, a substrate having a layer of tungsten silicide was placed in the chamber and N ₂ diluted 5% F ₂ was introduced into the chamber from a single gas line. . The pressure in the chamber was set to and maintained at 40 Torr. The etch rate is determined by F ₂
This was done by measuring the thickness of the tungsten silicide layer before and after gas exposure. The measurement of the thickness is determined by a profilome
r) and a 4-point probe. The results of these experiments are shown in FIG. 5, which shows the log (in Angstroms) of the etch rate of the deposited tungsten silicide,
3 is a graph showing a function of temperature (unit is K (Kelvin)). Temperature was measured on the susceptor. When the temperature of the 5 susceptor is 550 ° C., the wafer temperature is 25
５０50 ° C. lower.

As is apparent from FIG. 5, at 550 ° C.,
Tungsten silicide etch rate is 5% diluted F
_In No. _2, it was 20,000 Å / min. At 250 ° C., the etch rate is 8820 Å / min. At 158 ° C., the etch rate is 5500 ° C.
At 70 ° C., the etch rate was 1470 Å / min, and at 50 ° C., 490 Å / min. Thus, the results of these experiments indicate that the etch rates are significantly higher at higher temperatures. However, these experiments show that tungsten silicide is etched even at temperatures as low as 50 ° C.

It is important to note that etching occurs even at low temperatures. Some processing chambers that perform thermal reactions, such as CVD deposition of tungsten silicide, heat a reaction area near the surface of the substrate being processed to a relatively high temperature, such as about 550 ° C.
Such heating may be performed, for example, by a resistance heating platen. Other areas of the chamber, such as the outer chamber walls, are kept cooler (eg, about 50 ° C.). In such systems, undesired deposition occurs in or around hot areas, but deposition does not occur in cold places. In such a system, the chamber can be heated during the cleaning step in the same manner as used in the deposition process. That is,
Hot regions may form around the platen surface, while other regions of the chamber may have cooler regions. F
_{Since the} mixed gas etches the tungsten silicide even at a temperature of 50 ° C. or less, the deposits accumulated in such a low temperature region can be appropriately removed during the F ₂ chamber cleaning operation of the present invention.

In another set of experiments, a substrate having a layer of tungsten silicide was placed in a chamber and N ₂ diluted 20% F ₂ was introduced into the chamber. In these experiments, measurements were taken to determine the etch rate of the tungsten silicide film as a function of temperature, pressure, and total gas flow. Graphs showing the results of each experiment are shown in FIGS.

FIG. 6 is a graph showing the effect of temperature on the etch rate of tungsten silicide. During the experiment, a 20% F ₂ mixed gas was introduced at a flow rate of ₂ slm, the chamber pressure was maintained at 5 Torr, and the substrate temperature was changed.
As can be seen from this figure, up to a temperature of 500 ° C., as the temperature increases, the etch rate also increases.

FIG. 7 is a graph showing the effect of pressure on the etch rate of tungsten silicide. During the experiment, a 20% F ₂ mixed gas was introduced at flow rates of 1 slm and 2 slm according to the measurement, the substrate temperature was maintained at 550 ° C., and the chamber pressure was changed. As can be seen from this figure, increasing the pressure from 1 Torr to 20 Torr increases the etch rate. When the pressure is at a high level (about 15 to
The rate of increase in etch rate of 20 Torr) is lower than at lower pressures.

FIG. 8 is a graph showing the influence of the gas flow rate on the etch rate of tungsten silicide. During the experiment, the chamber was maintained at 1, 3, 5, 10, or 20 Torr, depending on the measurement, the substrate temperature was kept constant at 550 ° C., and a 20% F ₂ mixed gas was introduced at a flow rate of 1 slm or 2 slm. As can be seen from this figure, as the gas flow rate increases, the etch rate of tungsten silicide also increases. Even more strikingly, etch rates have been shown to increase with chamber pressures above 5 Torr.

While the invention has been described with several embodiments, other equivalent or alternative ways of cleaning the processing chamber according to the invention will be apparent to those skilled in the art. . These equivalent or alternative methods are within the scope of the present invention.

[0048]

As described in detail above, the present invention provides a method for cleaning a CVD or other type of process chamber without PFC gas.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of one specific example of a simple chemical vapor deposition apparatus according to the present invention.

FIG. 2 is a cross-sectional view of a specific example of a resistance heating susceptor used in the chamber of FIG. 1 for fixing a substrate to be processed in the chamber.

FIG. 3 is a flowchart of wafer processing in one embodiment of the method of the present invention.

FIG. 4 is a graph showing the effect of increasing the introduction rate of F _{2 on} the etch rate of a deposit.

FIG. 5 is a graph showing the etch rate of tungsten silicide as a function of temperature when exposed to a mixed gas of F ₂ diluted to 5% with an N ₂ carrier gas.

FIG. 6 is a graph showing the etch rate of tungsten silicide as a function of temperature when exposed to a mixed gas obtained by diluting F ₂ to 20% with an N ₂ carrier gas.

FIG. 7 is a graph showing the etch rate of tungsten silicide as a function of pressure when exposed to a mixed gas of F ₂ diluted to 20% with a N ₂ carrier gas.

FIG. 8 is a graph showing the etch rate of tungsten silicide as a function of gas flow rate when exposed to a mixed gas of F ₂ diluted to 20% with a N ₂ carrier gas.

[Explanation of symbols]

10 reactor, 12 vacuum chamber, 14 gas distribution manifold, 16 wafer, 18 susceptor, 20
Motor, 22 pins, 32 processing positions, 54
Purge guide.

Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical indication H01L 21/306 H01L 21/304 341Z 21/304 341 21/302 P (72) Inventor Chau Jun United States of America, California Ridge Creek Court 11764 (72) Inventor Shan May United States, California, Saratoga, Cote de Aguero 12881 (72) Inventor Sinha Ashok United States of America, California, Palo Alto, Hubbert Drive 4176 (72) Inventor Castel Eguir United States, California, Sunnyvale, Yates Court 843

Claims (19)

[Claims] 1. A method for removing particles and residues accumulated inside a substrate processing chamber in a substrate processing operation, comprising: (a) molecular fluorine (F ₂ ) and an inert gas after completion of the substrate processing operation; Introducing an etchant gas into the chamber, comprising: (b) heating at least a portion of the chamber to a temperature of 400 ° C. or higher to cause the etchant gas to react with the particles and the residue; Reducing the particles and the residue that have accumulated in the chamber. 2. The method according to claim 1, wherein said etchant gas has a concentration of about 1-2.
The method according to claim 1 having a 0% molecular fluorine (F _2). 3. The method according to claim 1, wherein the etchant gas has a concentration of about 10%.
The method of claim 2 having a molecular fluorine (F ₂₎ of less than. 4. The method according to claim 1, wherein the inert gas includes nitrogen (N ₂ );
Argon (Ar), neon (Ne), and helium (H
3. The method of claim 2, wherein the method is selected from the group consisting of: e). 5. The method of claim 2, wherein said particles and said residue have been deposited inside said chamber by chemical vapor deposition. 6. The method of claim 5, wherein said particles and said residue have been deposited inside said chamber by a chemical vapor deposition reaction of a tungsten containing gas. 7. The method according to claim 1, wherein the chamber has a temperature of about 400 to 650.
7. The method of claim 6, wherein the method is heated to <RTIgt; 8. The method of claim 7, further comprising the step of setting and maintaining the pressure in said chamber at a level of about 1 to 100 Torr. 9. A method for removing particles and residues accumulated inside a substrate processing chamber in a substrate processing operation, comprising: (a) after the substrate processing operation is completed, molecular fluorine (F ₂ ) and an inert gas; Introducing an etchant gas into the chamber, comprising: (b) heating at least a portion of the chamber to a temperature of 400 ° C. or higher; and (c) generating a plasma from the etchant gas;
Reacting the etchant gas with the particles and the residue to reduce the particles and the residue accumulated in the chamber, generating the plasma to etch away the particles from the chamber. Energy for perfluoro compound gas (PFC)
Gas) is used as an etchant and the energy is lower than that required when it is used. 10. A method for manufacturing an integrated circuit in a processing chamber, comprising: (a) introducing a wafer into the chamber; and (b) performing processing on the wafer in the chamber. (C) removing the wafer from the chamber; (d) removing the wafer from the chamber; and (c) removing the wafer from the chamber. Introducing an etchant gas containing molecular fluorine (F ₂ ) and an inert gas into the chamber; and (e) setting the pressure in the chamber to at least 1 Torr, Maintaining (f) at least a portion of the chamber by at least 4
Heating to 00 ° C. and reacting the particles and residues with the etchant gas to etch away particles and residues from the unwanted areas of the chamber. 11. The method of claim 10, wherein step (b) comprises performing a chemical vapor deposition. 12. The step of performing chemical vapor deposition comprises: (i) introducing a process gas comprising tungsten and hydrogen into the chamber; and (ii) heating the chamber to a temperature of about 400-500 ° C. 12. The method of claim 11, comprising: (iii) maintaining the chamber at a pressure of about 10 to 100 Torr. 13. The method of claim 12, wherein said process gas comprises tungsten hexafluoride (WF ₆ ). 14. The process gas may be silane (SiH
The method of claim 13, having both or either ₄₎ and molecular hydrogen (H _2). 15. The step (e) includes setting and maintaining a pressure of about 10 to 40 Torr inside the chamber, and the step (f) includes placing the wafer at about 425 to 500 Torr. The method according to claim 10, comprising the step of heating to a temperature of ° C. 16. A substrate processing system, comprising: a housing forming a vacuum chamber; a substrate holder disposed inside the housing for holding a substrate; and a gas distributor for introducing a process gas into the vacuum chamber. A gas mixing chamber coupled to a postponed gas distributor and mixing a plurality of gases therein to produce the process gas; anda gas coupling chamber coupled to the gas mixing chamber for introducing a plurality of gases into the gas mixing chamber. A gas distribution system, a heater for heating the substrate, a vacuum system for controlling a pressure in the vacuum chamber, a gas distributor, the heater, and a controller for controlling the vacuum system. Instructing operation of the controller and the substrate processing system A memory coupled to the controller, comprising a computer readable medium having a computer readable program for controlling the heater, the vacuum system, and the gas distribution system. Introducing the process gas into the vacuum chamber and maintaining a chamber temperature and pressure within a selected range to perform a substrate processing operation that leaves particles and residues in the vacuum chamber; Controlling a first set of instructions; and controlling the heater to reduce a portion of the chamber for at least about 40 for a first period after the substrate processing operation.
A second set of instructions, heating to a temperature of 0 ° C., controlling said gas distribution system,
During the first period, 1% to 30% dilution molecular fluorine (F ₂₎
Introducing an etchant gas comprising a gas mixture into the gas mixing chamber to remove some of the particles and residues.
And a set of instructions. 17. The method according to claim 17, wherein the third set of instructions controls the gas distribution system to provide about 10%
Apparatus according to claim 16 for introducing an etchant gas having a concentration of molecular fluorine (F ₂₎ of less than. 18. The computer readable program further controls the vacuum system to set and maintain the vacuum chamber at a pressure greater than about 1 Torr during the first time period. 17. The set of instructions of
An apparatus according to claim 1. 19. The fourth set of instructions controls the vacuum system to set and maintain the vacuum chamber at a pressure of about 1-100 Torr during the first time period. 19. The device according to 18.