The disclosure relates to a method for processing a substrate, and more particularly to controlling a size of particles in order to prevent a quality of film and operating efficiency of a substrate processing apparatus from being deteriorated.
In a semiconductor film deposition process, a film may be deposited on a substrate by supplying a source gas and a reactant to a reactor. But as the number of processed substrate increases, the film may be also deposited on the inner surface of the reactor, which then may diffuse in a reaction space and drop onto the substrate in the form of particles.
Particles can contaminate the reactor, destroy device structures on the substrate, and cause malfunction and defects of the device. Particularly, the size of the particles may be increased with a greater the number of processed substrates; this can lead to defects on the substrate and the lowered yield of devices.
Therefore, it may be ideal for a process not to generate particles. But the film deposition process is based on a gas reaction between gases, so it may not be possible for the process not to generate particles.
A conventional dry cleaning process as shown in
A wet cleaning is another method of cleaning a reactor as shown in
But the wet cleaning process includes lowering a reactor temperature, disassembling a reactor, a wet cleaning, reassembling the reactor, raising a reactor temperature, and seasoning the reactor to create an environment for a normal process. This may require a lot of time and may lower an operating efficiency of the substrate processing apparatus.
The present disclosure provides a method for controlling a thickness of the particles on a substrate.
In one embodiment, a particle with a first particle thickness may be formed on a film with a first film thickness, followed by a plasma treatment. The first particle thickness of the particle may be reduced to a second particle thickness below an allowable limit and the first film thickness of the film may be reduced to a second film thickness by the plasma treatment.
In another embodiment, a particle with a first particle thickness may be formed on a first film with a first film thickness, followed by a plasma treatment. The first particle thickness of the particle may be reduced to a second particle thickness below an allowable limit and the first film thickness of the first film may be reduced to a second film thickness by the plasma treatment. After the plasma treatment, a second film with a third film thickness may be deposited on the first film with a second film thickness and the particle may be buried in the second film with a third film thickness.
The disclosure may have technical advantages of reducing the thickness of particles formed on the film by plasma treatment, and preventing a quality of a substrate processing process and device performances from being deteriorated accordingly.
The disclosure may have additional technical advantages of extending a dry cleaning cycle or a wet cleaning cycle, improving an uptime and operating efficiency of the substrate processing apparatus and a throughput per unit time.
The above and other aspects, features, and advantages of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:
The disclosure is to solve the aforementioned problems of particle generation. More particularly, the disclosure provides a method of controlling a size of the particles formed on a substrate during a substrate processing process without a dry cleaning process or a wet cleaning process. The method may reduce device failure and improve an uptime and an operating efficiency of the substrate processing apparatus.
The disclosure provides a plasma treatment to control a size of the particles formed on a substrate during a substrate processing process, such as film deposition process. More particularly, a sputtering by the plasma treatment may be provided to reduce the size of the particles to below the allowable limit. The term ‘allowable limit’ here means an upper limit of the size of the particle that does not affect the quality of the substrate processing process. For instance, if the size of particles are below the allowable limit even though particles are formed on the substrate, the quality of film and the device performance are not deteriorated. Therefore, the disclosure provides a method for controlling the size of particles below the allowable limit by the plasma treatment.
In
In
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In
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STEP 1(S1): a film may be deposited on a substrate by supplying a source gas, a reactant, and a purge gas to the substrate. The film may be deposited by at least one of methods of atomic layer deposition (ALD), plasma atomic layer deposition (PEALD), chemical vapor deposition (CVD), plasma chemical vapor deposition (PECVD) and pulsed plasma chemical vapor deposition (Pulsed PECVD). The STEP 1 may be repeated until the film reaches a first film thickness. For instance, in the method of ALD, the deposition process may be carried out by inputting the number of necessary cycles based on the film growth rate per unit cycle in the controller, e.g. PC controller. In the method of CVD, the deposition process may be carried out by inputting the time necessary to deposit the film with the first film thickness based on the film growth rate per unit time in the controller, e.g. PC controller.
In STEP 1(S1), particles with a first particle thickness may be formed on the film during deposition of the film on the substrate. The particles may be generated from film deposited on an inner surface of a reactor and may fall onto the substrate, or may be formed by the abnormal growth of the film on the substrate during a chemical reaction between gases.
STEP 2(S2): A plasma treatment may be carried out on the film with the first film thickness and the particles with the first particles thickness formed on the first film. In STEP 2, a sputtering caused by active species may be carried out on the film and the particles. The plasma may be generated by supplying RF power to the reactor and activating a reactant and a purge gas in order to generate active species. The source gas may not be provided in this step.
In STEP 2(S2), the plasma treatment may result in the reduction of the thickness of the film and the particles. For instance, the first film thickness may be reduced to a second film thickness and the first particle thickness may be reduce to a second particle thickness.
STEP 1(S1'): a first film may be deposited on a substrate by supplying a source gas, a reactant, and a purge gas to the substrate. The first film may be deposited by at least one of methods of atomic layer deposition (ALD), plasma atomic layer deposition (PEALD), chemical vapor deposition (CVD), plasma chemical vapor deposition (PECVD) and pulsed plasma chemical vapor deposition (Pulsed PECVD). The STEP 1 may be carried out until the first film reaches a first film thickness. For instance, in the method of ALD, the deposition process may be carried out by inputting the number of necessary cycles based on the film growth rate per unit cycle in the controller, e.g. PC controller. In the method of CVD, the deposition process may be carried out by inputting the time necessary to deposit the film with the first film thickness based on the film growth rate per unit time in the controller, e.g. PC controller.
In STEP 1(S′), particles with a first particle thickness may be formed on the first film during depositing the first film on the substrate. The particles may be generated from a film deposited on an inner surface of a reactor and may fall onto the substrate, or may be formed by the abnormal growth of the first film on the substrate during a chemical reaction between gases.
STEP 2(S2'): A plasma treatment may be carried out on the first film and the particles formed on the first film. In STEP 2, a sputtering caused by active species is carried out on the first film and the particles. The plasma is generated by supplying RF power to the reactor and activates a reactant and a purge gas, except for a source gas, in order to generate active species.
The plasma treatment may result in the reduction of the thicknesses of the film and the particles. For instance, the first film thickness may be reduced to the second film thickness and the first particle thickness may be reduced to the second particle thickness.
STEP 3(S3'): A second film with a third film thickness may be deposited on the first film with the second film thickness. The second film may be deposited by the same method as the STEP 1(S1'). The second film may be identical to the first film or different in another selective embodiment.
The sum of the second film thickness of the first film and the third film thickness of the second film may be the same as the first film thickness of the first film or be thicker than the first film thickness of the first film.
In STEP 3(S3'), the second film with the third film thickness may be additionally deposited on the first film with the second film thickness. As a result, the particles with the second particle thickness may be buried in the second film with the third film thickness. Therefore, it may have technical advantages of eliminating particles from the film and facilitating more to form a semiconductor circuit structures in the subsequent process.
In STEP 1, a first SiO2 film may be deposited on the substrate. The STEP 1 may comprise several sub-steps, such as a source supply step t1, a source purge step t2, a plasma supply step t3, and a reactant purge step t4. A Si source gas and a plasma may be supplied alternately, and oxygen gas as reactant and an inert gas as purge gas, e.g. Ar, may be continuously supplied throughout the steps t1 to t4. The plasma may be generated by activating a reactant and Ar gas by a RF power supplied to the reactor. The oxygen gas may act as a reactive purge gas that chemically reacts with Si source gas only when activated by plasma at step t3. In STEP 1, Si source gas and activated oxygen gas may chemically react and deposit a first SiO2 film with a first film thickness. The STEP 1 may be repeated a plurality of times (‘M’ times) until the first SiO2 film achieves a target film thickness.
In STEP 1, particles with a first particle thickness may be formed on the first SiO2 film with the first film thickness during deposition of the first SiO2 film onto the substrate. The particles may be generated from a SiO2 film deposited on an inner surface of a reactor and may fall onto the substrate, or may be formed by the abnormal growth of the first SiO2 film on the substrate during a chemical reaction between Si source and activated oxygen gas.
In STEP 2, a plasma treatment may be carried out on the first SiO2 film with the first film thickness and the particles with the first particle thickness. The plasma treatment may be carried out by activating oxygen gas and Ar gas by RF power supplied to a reactor. As the Si source gas is not provided, an additional SiO2 film is not deposited in STEP 2. Instead, a sputtering by activated oxygen gas and Ar gas may be carried out on the first SiO2 film and the particles. As a result, the thickness of the first SiO2 film and particles may be reduced. That is, the first film thickness of the first SiO2 film and the first particle thickness of particles may be reduced to the second film thickness of the first SiO2 film and the second particle thickness of particles by the plasma treatment. The STEP 2 may be repeated a plurality times (‘N’ times).
In another selective embodiment, a high frequency RF power (HRF) and a low frequency RF power (LRF) may be supplied together in order to increase the sputtering effect.
In another selective embodiment, the RF power supplied during the STEP 2 may be greater than the RF power supplied during the STEP 1.
In another selective embodiment, the RF power supplying time t5 in the STEP 2 may be longer than the RF power supplying time t3 in STEP 1.
In STEP 3, a second SiO2 film with a third film thickness may be deposited on the first SiO2 film with the second film thickness. The STEP 3 may comprise several sub-steps, such as a source supply step t7, a source purge step t8, a plasma supply step t9, and a reactant purge step t10. A Si source gas and a RF power may be supplied alternately and oxygen gas as reactant and Ar gas as purge as are continuously supplied throughout the steps t7 to t10. The plasma may be generated by activating a reactant and Ar gas by a RF power supplied to the reactor. The second SiO2 film may be deposited by the same method as the first SiO2 film in STEP 1. The STEP 3 may be repeated a plurality of times until the second SiO2 film achieves the third film thickness (‘X’ times).
The sum of the second film thickness of the first SiO2 film and the third film thickness of the second SiO2 film may be the same as the first film thickness of the first SiO2 film or be thicker than the first film thickness of the first SiO2 film.
In STEP 3, the second SiO2 film with the third film thickness is additionally deposited on the first SiO2 film. So the particles may be buried in the second SiO2 film with the third film thickness. Therefore, it may have technical advantages of eliminating particles from the film and facilitating formation of semiconductor circuit structures in the subsequent process.
In STEP 1 to STEP 3 of
The STEP 1 and the STEP 2 of
Table 1 shows process conditions for STEP 1 for SiO2 film deposition and STEP 2 for plasma treatment of
In Table 1, a single frequency RF power, that is, a high frequency RF power is supplied to the reactor during a deposition step and a dual frequency RF power, that is, a high frequency RF power and a low frequency RF power are supplied during a plasma treatment step.
The process conditions may be adjusted to increase a sputtering effect in plasma treatment step. For instance, in Table 1, a RF power supplying time is longer and a RF power is greater than those in the deposition step. And a dual frequency RF power is supplied rather than a single frequency RF power. The reaction gap is maintained small and the process pressure is maintained low below 10 Torr to increase a sputtering effect as well.
In Table 1, DIPAS (diisoprophylaminosilane; SiH3N(iPr)2) as a Si source gas and oxygen gas as a reactant may be supplied to deposit a SiO2 film on the semiconductor circuit structure formed on the substrate. But the Si source is not limited thereto. The Si source may comprise at least one of: aminosilane, iodosilane, or silicon halide. For instance, the Si source may comprise at least one of: TSA, (SiH3)3N; DSO, (SiH3)2; DSMA, (SiH3)2NMe; DSEA, (SiH3)2NEt; DSIPA, (SiH3)2N(iPr); DSTBA, (SiH3)2N(tBu); DEAS, SiH3NEt2; DTBAS, SiH3N(tBu)2; BDEAS, SiH2(NEt2)2; BDMAS, SiH2(NMe2)2; BTBAS, SiH2(NHtBu)2; BITS, SiH2(NHSiMe3)2; TEOS, Si(OEt)4; SiCl4; HCD, Si2CI6; DCS, SiH2CI2; 3DMAS, SiH(N(Me)2)3; BEMAS, SiH2[N(Et)(Me)]2; AHEAD, Si2(NHEt)6; TEAS, Si(NHEt)4; Si3H8 ;SiHl3; or SiH2l2.
The oxygen gas may comprise at least one of: O2, O3, CO2, H2O, NO2, or N2O; or a combination thereof.
In another embodiment, the first film and the second film may be SiN films and the reactant may be nitrogen-containing gas. For instance, it may comprise at least one of: N2, NH3, N2O, or NO2, or combination thereof.
As shown in
According to
The disclosure has another technical advantages of extending a dry cleaning cycle or a wet cleaning cycle, improving an uptime and operating efficiency of the substrate processing apparatus and a throughput per unit time.
In
The process gas is exhausted through an exhaust unit 8, which may be an exhaust pump. The gas supply unit 2 is connected to the RF power supply unit. The RF power supply unit may comprise: a matching network 5, a high frequency RF power generator 6, or a low frequency RF power generator 7. In an embodiment, the high frequency RF power generator 6 may supply a high frequency RF power to the reactor 1 during a deposition step. In another embodiment, the high frequency RF power generator 6 and the low frequency RF power generator 7 may supply a high frequency RF power and a low frequency RF power to the reactor 1 during a plasma treatment step.
It should be understood that embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments. While one or more embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure as defined by the following claims.
This application claims priority to U.S. Provisional Pat. Application Serial No. 63/243,970 filed Sep. 14, 2021, titled METHOD FOR PROCESSING A SUBSTRATE, the disclosure of which is hereby incorporated by reference in its entirety.
Number | Date | Country | |
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63243970 | Sep 2021 | US |