Substrate processing method
By supplying a specific gas on the patterned substrate and applying variable frequency RF power, a low-impurity amorphous TiN film is formed, which solves the problem of difficult removal of TiN film impurities in the existing technology and improves the selectivity and quality of the film.
Patent Information
- Application Number
- CN202410934844.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-07-17
- Filing Date
- 2024-07-12
- Publication Date
- 2025-01-24
AI Technical Summary
In the prior art, when forming a TiN film, it is difficult to effectively remove impurities, resulting in deterioration of the film quality, and high-temperature treatment can easily damage the structure of the crystalline TiN film.
Use the pattern substrate to activate the second gas and the third gases to activate the transformer RF power through the supply of the first and second gases on the pattern base, and to activate the second gases and the third gases to form an amorphous tin membrane with low impurities.
A amorphous TIN membrane with low impurities is formed under low temperature conditions, avoiding the problem of difficulty removing impurities, and improving the selectivity and quality of the membrane.
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Figure CN119361415A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a method for forming a semiconductor film on a substrate, and more particularly to a method for forming a titanium nitride (TiN) isolation film on a pattern structure. Background Art
[0002] As the size of semiconductor devices continues to shrink, the line width of device circuits becomes narrower. Therefore, the technical difficulty of forming an isolation film on a pattern increases. In order to overcome this problem, a DPT (double patterning technology) process is adopted. In the existing DPT process, a SiO2 film is formed on the pattern as an isolation film. However, as the line width becomes narrower, a new isolation film with higher selectivity than the existing SiO2 film is needed on the pattern.
[0003] TiN film is introduced to replace SiO2 film as an isolation film, and the film is required to have low impurities to achieve high selectivity. For this reason, the TiN film is formed at a high temperature of more than 300°C and exposed to plasma for a long time to remove impurities (such as carbon and oxygen) by ion bombardment. However, the processing conditions lead to crystallized TiN film and damage to sublayers such as hard masks. Crystallized TiN film has a strong bonding structure, which makes it difficult to remove impurities therefrom. Due to the continuous ion bombardment of the reactor, the long-term exposure of the reactor to plasma may cause the temperature in the reactor to rise and cause the degradation of the film quality in the subsequent process. Therefore, a method for forming a TiN film to avoid the above problems is needed. Summary of the invention
[0004] The present invention discloses a method for forming a film on a pattern, in particular, an amorphous TiN film with low impurities as an isolation film on the pattern.
[0005] In one or more embodiments, a method for forming a film on a pattern substrate may include the following steps: providing the substrate to a reaction chamber, supplying a first gas to the reaction chamber, supplying a second gas to the reaction chamber, and applying power to the reaction chamber, wherein the frequency of the power may be a variable frequency and the second gas may be activated by the power.
[0006] In one or more embodiments, the film may include amorphous TiN with impurities of 25% or less.
[0007] In one or more embodiments, the impurities may include at least one of oxygen, carbon, or a mixture thereof.
[0008] In one or more embodiments, during application of power to the reaction chamber, 5 W or less of reflected power is generated.
[0009] In one or more embodiments, the first gas may include at least one of: tetrakisdimethylamidotitanium (Ti[N(CH3)2]4, TDMAT), tetrakisdiethylamidotitanium ([(C2H5)2N]4Ti, TDEAT), tetraethylmethylamidotitanium (Ti[(CH3C2H5)N]4, TEMAT), titanium isopropoxide (Ti[OCH(CH3)2], TTIP), titanium chloride (TiCl4), derivatives thereof, or mixtures thereof.
[0010] In one or more embodiments, the second gas includes at least one of: N2, NH3, NH4, N2H2, N2H4, or a mixture thereof.
[0011] In one or more embodiments, the method further includes supplying a third gas to the reaction chamber, and simultaneously activating the second gas and the third gas by power.
[0012] In one or more embodiments, the method may further include treating the film by supplying a third gas to the reaction chamber and activating the third gas by power after forming the film by supplying the first gas, supplying the second gas, and activating the second gas by power.
[0013] In one or more embodiments, the third gas includes at least one of hydrogen gas, atomic hydrogen, or a mixture thereof.
[0014] In one or more embodiments, the method of forming a film is performed between about 100°C and about 250°C or between about 150°C and about 200°C.
[0015] In one or more embodiments, a power between about 200 W and about 500 W or between about 250 W and about 450 W is applied to the reaction chamber.
[0016] In one or more embodiments, a method of patterning a substrate may include the following steps: providing a substrate to a reaction chamber, forming a first film on the substrate, forming a second film on the first film, patterning the second film, forming a third film on the second film, selectively removing the third film, removing the second film, selectively removing the first film, and removing the third film, wherein the third film is amorphous TiN.
[0017] In one or more embodiments, the first film may include amorphous carbon, and the second film may include amorphous silicon.
[0018] In one or more embodiments, the selective removal of the third film is performed by etch-back.
[0019] In one or more embodiments, the selectively removing the second film and the removing the first film are performed by selective etching.
[0020] In one or more embodiments, the removing of the third film is performed by at least one of ashing and stripping.
[0021] This summary is provided to introduce some concepts in a simplified form. These concepts are further described in detail in the detailed description of the example embodiments disclosed below. This summary is not intended to identify the key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 A substrate processing method according to an embodiment of the present disclosure is shown.
[0023] Figure 2 A substrate processing method according to another embodiment of the present disclosure is shown.
[0024] Figure 3A and Figure 3B A timing diagram of a sub-state processing method according to the present disclosure is shown.
[0025] Figure 4A and Figure 4B The plasma process and the matching time according to the impedance matching type are shown.
[0026] Figure 5A and Figure 5B The RF power modes are shown when the VF (variable frequency) mode is turned off (ie, fixed frequency mode in the conventional process) and turned on (ie, variable frequency mode in the embodiment of the present disclosure).
[0027] Fig. 6A and Figure 6B XRD data are shown, showing the crystalline TiN film and the amount of impurities such as carbon and oxygen, respectively.
[0028] Fig. 7A and Figure 7B XRD data are shown, which show the amorphous TiN film and the amounts of impurities such as carbon and oxygen, respectively.
[0029] Figure 8 A patterning process that can form a TiN isolation film according to the present disclosure is shown.
[0030] Fig. 9A The film thickness variation between batches and between reaction chambers in the same batch in fixed frequency mode is shown.
[0031] Fig. 9B The film thickness variation between batches and between reaction chambers in the same batch in variable frequency mode is shown.
[0032] Fig.10 A multi-reaction chamber system according to the present disclosure is shown.
[0033] It should be understood that the elements in the drawings are shown for simplicity and clarity and are not necessarily drawn to scale. For example, the size of some elements in the drawings may be exaggerated relative to other elements to help improve the understanding of the illustrated embodiments of the present disclosure. DETAILED DESCRIPTION
[0034] Although certain embodiments and examples are disclosed below, those skilled in the art will appreciate that the invention extends beyond the specifically disclosed embodiments and / or uses of the invention and their obvious modifications and equivalents. Therefore, it is intended that the scope of the disclosed invention should not be limited by the specifically disclosed embodiments described below.
[0035] As used herein, the term "substrate" may refer to any one or more underlying materials, including any one or more underlying materials that may be modified or on which a device, circuit, or film may be formed. A "substrate" may be continuous or non-continuous; rigid or flexible; solid or porous; and combinations thereof. A substrate may be in any form, such as a powder, a plate, or a workpiece. A plate-like substrate may include wafers of various shapes and sizes. A substrate may be made of semiconductor materials, including, for example, silicon, silicon germanium, silicon oxide, gallium arsenide, gallium nitride, and silicon carbide.
[0036] The illustrations presented herein are not meant to be actual views of any particular material, structure, or device but are merely idealized representations used to describe embodiments of the present disclosure.
[0037] The specific embodiments shown and described are illustrations of the present invention and its best mode and are not intended to limit the scope of these aspects and embodiments in any way. In fact, for the sake of brevity, the traditional manufacturing, connection, preparation and other functional aspects of the system may not be described in detail. In addition, the connecting lines shown in the various figures are intended to represent exemplary functional relationships and / or physical connections between various elements. Many alternative or additional functional relationships or physical connections may exist in actual systems, and / or may not exist in some embodiments.
[0038] Figure 1 A substrate processing method according to an embodiment of the present disclosure is shown.
[0039] In step 110 of the substrate processing method 100, a substrate may be provided to a reaction chamber. The substrate may have a semiconductor circuit including a 3D structure and a gap formed thereon. The reaction chamber may include equipment in which the substrate is processed. In the reaction chamber, deposition, gap filling, etching, or any other substrate processing process using plasma may be performed on the substrate.
[0040] In step 120, a first gas may be supplied to the substrate. The first gas may include a titanium-containing gas. The first gas may include at least one of tetrakis dimethylamidotitanium (Ti[N(CH3)2]4, TDMAT), tetrakis diethylamidotitanium ([(C2H5)2N]4Ti, TDEAT), tetraethylmethylamidotitanium (Ti[(CH3C2H5)N]4, TEMAT), titanium isopropoxide (Ti[OCH(CH3)2], TTIP), titanium chloride (TiCl4), derivatives thereof, or mixtures thereof.
[0041] The first gas may be adsorbed on the substrate. Although not mentioned in the substrate processing method 100, step 120 may be followed by a purge step to purge unused first gas and byproducts out of the reaction chamber.
[0042] In step 130, the second gas and the third gas may be supplied to the reaction chamber. The second gas and the third gas may be supplied simultaneously. For example, the second gas and the third gas may be continuously supplied to the reaction chamber throughout the process. In another embodiment, the second gas may be continuously supplied and the third gas may be intermittently supplied.
[0043] The second gas may include a nitrogen-containing gas. The second gas may include at least one of the following: N2, NH3, NH4, N2H2, N2H4, or a mixture thereof.
[0044] The third gas may include a hydrogen-containing gas. The third gas may include at least one of hydrogen gas, atomic hydrogen, or a mixture thereof.
[0045] In step 140, power may be applied to the reaction chamber. The power may be RF power and applied to the reaction chamber in situ. In other embodiments, the power may be applied ex situ.
[0046] In one embodiment, a power between about 200 W and about 500 W may be applied to the reaction chamber, or a power between about 250 W and about 450 W may be applied to the reaction chamber.
[0047] The frequency of the power may not be a fixed frequency. In other words, the frequency of the power may be a variable frequency. That is, the impedance between the reaction chamber and the matching network may be matched by changing the frequency of the power through an algorithm or firmware embedded in the power generator, rather than by mechanical movement of the VVC (vacuum variable capacitor) of the matching network.
[0048] In this embodiment, applying variable frequency RF power to the reaction chamber can result in a reflected power of 5 W or less. Thus, a more efficient plasma process is possible.
[0049] Power may be applied to activate the second gas, thereby generating radicals of the second gas (eg, nitrogen radicals). The activated second gas may chemically react with the first gas adsorbed on the substrate and form a film (eg, TiN).
[0050] The power may also activate a third gas (eg, hydrogen radicals). The activated third gas may chemically react with impurities such as carbon and oxygen present in the film and help remove them from the film. The second gas and the third gas may be supplied and activated simultaneously.
[0051] Although not mentioned in the substrate processing method 100 , step 140 may be followed by a purge step to purge unreacted second and third gases and by-products out of the reaction chamber.
[0052] In step 150, the film thickness may be measured. If the film thickness does not reach the target thickness, steps 120, 130, and 140 may be repeated several times (X times). If the film thickness reaches the target thickness, the process may end in step 160. The target thickness may be set by inputting a certain number of cycles into a control system (not shown) of the reaction chamber.
[0053] Figure 2 A substrate processing method according to another embodiment of the present invention is shown.
[0054] The substrate processing method 200 may include a deposition step including steps 220 to 240 and a processing step including steps 260 to 270 .
[0055] In step 210 of the substrate processing method 200, a substrate may be provided to a reaction chamber. The substrate may have semiconductor circuits, such as 3D structures and gaps, formed thereon.
[0056] In step 220, a first gas may be supplied to the substrate. The first gas may include Figure 1 The first gas may include at least one of the following: tetrakis dimethylamidotitanium (Ti[N(CH3)2]4, TDMAT), tetrakis diethylamidotitanium ([(C2H5)2N]4Ti, TDEAT), tetrakis ethylmethylamidotitanium (Ti[(CH3C2H5)N]4, TEMAT), titanium isopropoxide (Ti[OCH(CH3)2], TTIP), titanium chloride (TiCl4), derivatives thereof, or mixtures thereof.
[0057] The first gas may be adsorbed on the substrate. Although not mentioned in the substrate processing method 200, step 220 may be followed by a purge step to purge the unreacted first gas and byproducts out of the reaction chamber.
[0058] In step 230, a second gas may be supplied. The second gas may include at least one of the following: N2, NH3, NH4, N2H2, N2H4, or a mixture thereof. In another embodiment, the second gas may be continuously supplied throughout the deposition step.
[0059] In step 240, power may be applied to the reaction chamber. The power may be RF power and applied to the reaction chamber in situ. In other embodiments, the power may be applied ex situ.
[0060] In one embodiment, a power between about 200 W and about 500 W may be applied to the reaction chamber, or a power between about 250 W and about 450 W may be applied to the reaction chamber.
[0061] The frequency of the power may not be a fixed frequency. In other words, the frequency of the power may be a variable frequency. That is, the impedance between the reaction chamber and the power generator may be matched by changing the frequency of the power output by the power generator (e.g., an RF generator) by an algorithm or firmware embedded in the power generator, rather than by mechanical movement of a VVC (vacuum variable capacitor) of a matching network.
[0062] In this embodiment, applying variable frequency RF power to the reaction chamber may result in a reflected power of 5 W or less. Therefore, the efficiency of the plasma process may be improved.
[0063] Power may be applied to activate the second gas, thereby generating radicals of the second gas (eg, nitrogen radicals). The activated second gas may chemically react with the first gas adsorbed on the substrate and form a film (eg, TiN).
[0064] Although not mentioned in the substrate processing method 200 , step 240 may be followed by a purge step to purge unreacted second gas and byproducts out of the reaction chamber.
[0065] In step 250, the film thickness may be measured. If the film thickness does not reach the target thickness, steps 220, 230, and 240 may be repeated several times (X times). If the film thickness reaches the target thickness, the process may perform processing steps including steps 260 and 270. The target thickness may be set by inputting a certain number of cycles into a control system (not shown) of the reaction chamber.
[0066] In step 260, a third gas may be supplied. The third gas may include a hydrogen-containing gas. The third gas may include at least one of hydrogen gas, atomic hydrogen, or a mixture thereof.
[0067] In step 270, power may be applied to the reaction chamber. The power may be RF power and applied to the reaction chamber in situ. In other embodiments, the power may be applied ex situ.
[0068] In one embodiment, a power between about 200 W and about 500 W may be applied to the reaction chamber, or a power between about 250 W and about 450 W may be applied to the reaction chamber.
[0069] The frequency of the power may not be a fixed frequency. In other words, the frequency of the power may be a variable frequency. That is, the impedance between the reaction chamber and the matching network may be matched by changing the frequency of the power through an algorithm or firmware embedded in the power generator, rather than by mechanical movement of the VVC (vacuum variable capacitor) of the matching network.
[0070] In this embodiment, applying variable frequency RF power to the reaction chamber may result in a reflected power of 5 W or less. Therefore, the efficiency of the plasma process may be improved.
[0071] The power may also activate the third gas (eg, hydrogen radicals). The activated third gas may chemically react with impurities such as carbon and oxygen present in the film and help remove them from the film.
[0072] Although not mentioned in the substrate processing method 200, step 270 may be followed by a purge step to purge unreacted second and third gases and byproducts out of the reaction chamber. The third gas may be continuously supplied throughout the processing steps.
[0073] The processing steps including steps 260 and 270 may be repeated multiple times (Y times), and the deposition step and the processing step may be repeated multiple times, respectively. And the super cycle including the deposition step and the processing step may be repeated multiple times (Z cycles).
[0074] Figure 3A A timing diagram of a sub-state processing method according to the present disclosure is shown.
[0075] exist Figure 3A In step T1, a first gas may be supplied to the substrate. The first gas may include a titanium-containing gas. The first gas may include at least one of tetrakis dimethylamidotitanium (Ti[N(CH3)2]4, TDMAT), tetrakis diethylamidotitanium ([(C2H5)2N]4Ti, TDEAT), tetraethylmethylamidotitanium (Ti[(CH3C2H5)N]4, TEMAT), titanium isopropoxide (Ti[OCH(CH3)2], TTIP), titanium chloride (TiCl4), derivatives thereof, or mixtures thereof.
[0076] In steps T1 to T3, the second gas and the third gas may be continuously and simultaneously supplied to the reaction chamber. The second gas may include a nitrogen-containing gas, and the third gas may include a hydrogen-containing gas.
[0077] In step T3, power may be applied to the reaction chamber to activate the second gas and generate radicals of the second gas (eg, nitrogen radicals). The activated second gas may chemically react with the first gas adsorbed on the substrate to form a film (eg, TiN).
[0078] In step T3, the power may also activate a third gas (e.g., hydrogen radicals). The activated third gas may chemically react with impurities such as carbon and oxygen present in the film and help remove them from the film. Step T3 may correspond to Figure 1 In another embodiment, after the first gas is supplied and after the power is applied, purge steps T2 and T4 may be further added. Steps T1 to T4 may correspond to Figure 1 Steps 120 to 150. Figure 3A The method can be repeated multiple times (X times).
[0079] Figure 3B A timing diagram of a sub-state processing method according to the present disclosure is shown.
[0080] exist Figure 3B In step T1, a first gas may be supplied to the substrate. The first gas may include a titanium-containing gas. The first gas may include at least one of tetrakis dimethylamidotitanium (Ti[N(CH3)2]4, TDMAT), tetrakis diethylamidotitanium ([(C2H5)2N]4Ti, TDEAT), tetraethylmethylamidotitanium (Ti[(CH3C2H5)N]4, TEMAT), titanium isopropoxide (Ti[OCH(CH3)2], TTIP), titanium chloride (TiCl4), derivatives thereof, or mixtures thereof. Step T1 may correspond to Figure 2 Step 220.
[0081] In steps T1 to T3, the second gas may be continuously supplied to the reaction chamber. The second gas may include a nitrogen-containing gas.
[0082] In step T3, power may be applied to the reaction chamber to activate the second gas and generate free radicals of the second gas (e.g., nitrogen free radicals). The activated second gas may chemically react with the first gas adsorbed on the substrate and form a film (e.g., TiN). Steps T1 to T4 may be repeated multiple times (X times).
[0083] In step T5, a third gas may be supplied to the substrate. The third gas may include a hydrogen-containing gas. In step T5, power may be applied to activate the third gas (e.g., hydrogen radicals). The activated third gas may chemically react with impurities such as carbon and oxygen present in the film and help remove them from the film. Step T5 may be repeated multiple times (Y times). Steps T1 to T4 may correspond to Figure 2Steps 220 to 250, step T5 may correspond to Figure 2 The super cycle including the deposition steps T1 to T4 and the treatment step T5 may be repeated multiple times (Z times).
[0084] Figure 4A and Figure 4B The plasma process and the matching time according to the impedance matching type are shown.
[0085] Figure 4A A plasma process using conventional impedance matching is shown, where the power frequency is fixed and the VVC is shifted. Figure 4A As shown, conventional impedance matching between the power generator and the reactor can be performed by a mechanical matching network. In the matching network, two VVCs (vacuum variable capacitors) move back and forth to match the impedance between the power generator and the reactor. However, the mechanical movement of the VVC requires a period of time "a" for matching, and there is a limit in reducing the matching time accordingly, and usually high reflected power is generated as the plasma on time becomes shorter.
[0086] Figure 4B 1 shows a plasma process according to the present disclosure, wherein the power frequency is varied and the VVC is fixed. Figure 4B As shown, variable frequency (VF) tuning can be performed, where the frequency of the power from a power generator (e.g., an RF generator) can be changed, while the position of the VVC in the matching network is fixed. The frequency tuning of the power can be performed by controlling firmware (software) embedded in the power generator. Since the operation is controlled by software, the matching time "b" becomes shorter than Figure 4A The matching time "a" shown is much shorter. And the reflected power can be smaller compared to conventional matching networks. Therefore, substrate processing in variable frequency mode can be much faster than conventional fixed frequency methods.
[0087] In another embodiment, if Figure 4B As shown, in the variable frequency mode plasma process, during the time "c" after the matching is completed, the reflected power of 5 W or less may be maintained.
[0088] The power frequency variation can vary within the range of + / -5% of the set frequency. For example, in the case of 13MHz RF power, the frequency variation range can be between 12.8MHz and 14.3MHz. In the case of 27MHz RF power, the frequency variation range can be between 25.8MHz and 28.5MHz.
[0089] Figure 5A FIG. 4 shows the RF power mode when the VF (variable frequency) mode is turned off (i.e., the fixed frequency mode in the conventional process), while Figure 5BThe RF power mode is shown when the VF mode is turned on (ie, the variable frequency mode in the embodiment of the present disclosure).
[0090] exist Figure 5A In FIG. 4 , when processing a substrate in VF off mode, 400 W RF power at a frequency of 27 MHz is applied to the reaction chamber. Figure 5A As shown, 400W RF power (i.e., forward power) is applied, and the frequency is fixed at 27MHz. Two VVCs (vacuum variable capacitors) are kept moving in the matching network (i.e., load position and tuning position) as shown in ① to match the impedance between the reaction chamber and the RF power generator.
[0091] However, if Figure 5A As shown, 200 W of reflected power is generated. That is, about 50% of the forward power applied to the reaction chamber does not contribute to the process. Therefore, in order to compensate for the power loss, the RF power application time can be set longer, and / or high RF power can be applied, and / or the processing temperature can be set higher.
[0092] On the contrary, Figure 5B In the embodiment, when processing a substrate in VF on mode according to the present disclosure, 400W RF power with a frequency of 27MHz is applied to the reaction chamber. However, the frequency varies between 25.8MHz and 28.5MHz. In another embodiment, if a frequency of 13MHz is applied, the frequency can vary between 12.8MHz and 14.3MHz.
[0093] like Figure 5B As shown, 400W RF power (i.e., forward power) is applied, and the frequency changes as shown in ②. The two VVCs (vacuum variable capacitors) are fixed in the matching network (i.e., load position and tuning position). In other words, the impedance matching between the reaction chamber and the RF power generator can be achieved by keeping changing the frequency of the RF power, rather than by the mechanical movement of the VVC in the traditional matching network.
[0094] exist Figure 5B In the process, a very small intensity of reflected power can be generated. The reflected power can be 5W or less. That is, almost all the forward power applied to the reaction chamber contributes to the process. Therefore, high plasma efficiency can be maintained without setting a longer RF power application time and setting a higher processing temperature.
[0095] Fig. 6A and Figure 6B XRD data are shown, showing the crystalline TiN film and the amount of impurities such as carbon and oxygen, respectively.
[0096] However, if Fig. 6AAs shown, these conditions may result in a crystalline TiN film, where the TiN film grows in three crystal directions
[111] ,
[200] , and
[220] , represented by peaks at 2θ = about 37 degrees, 43 degrees, and 63 degrees, respectively. Due to the long RF time and high processing temperature, the TiN crystalline film with a strongly bonded structure may be difficult to remove impurities such as carbon and oxygen from the film.
[0097] like Figure 6B As shown, a TiN film formed in a conventional fixed frequency mode may produce carbon and oxygen impurities exceeding 28%, approaching 30%. High levels of impurities may cause uneven spacing between patterns in a patterning process such as a DPT process, and may cause defects in subsequent processes.
[0098] Compared with the plasma process in the VF off mode, the plasma process in the VF on mode can have a faster matching response time and higher RF power efficiency. For example, an amorphous TiN film with lower impurities can thus be formed at a low temperature (e.g., between about 100° C. and about 250° C., or between about 150° C. and about 200° C.), resulting in amorphous TiN film characteristics.
[0099] Fig. 7A and Figure 7B XRD data are shown, which show the amorphous TiN film and the amounts of impurities such as carbon and oxygen, respectively.
[0100] Fig. 7A It is shown that the TiN film formed in variable frequency mode (VF on mode) can be amorphous. This is due to the lack of Fig. 6A The peaks are shown for illustration.
[0101] Figure 7B It is shown that TiN films formed in variable frequency mode can produce 25% or less carbon and oxygen impurities, which is lower than Figure 6B Figure 2 shows carbon and oxygen impurities in a TiN film formed in a fixed frequency mode. In other words, the fraction of Ti and N in the film may be relatively high, especially higher than that obtained by Figure 6B Percentages of those obtained with the prior art process are shown.
[0102] In the VF on mode, a short RF application time and a low processing temperature can enable the formation of an amorphous TiN film having a relatively weakly bonded structure compared to a crystalline TiN film. Therefore, the weakly bonded structure facilitates the reaction between the activated third gas and impurities and the removal of impurities from the TiN film.
[0103] Table 1 shows the method for forming a Figure 8 The process conditions of the third film 330 (ie, TiN film) are shown in FIG.
[0104] Table 1 - Process conditions for forming a TiN film according to an embodiment of the present disclosure
[0105]
[0106]
[0107] Figure 8 A patterning process that can form a TiN isolation film according to the present disclosure is shown. The patterning process can be a double patterning technology (DPT) process.
[0108] exist Figure 8 In step A, a first film 310 may be formed on a substrate 300 as a hard mask, and then a second film 320 may be formed and patterned. The second film 320 may be a mandrel patterned on the first film 310. The first film may include a carbon-containing material such as amorphous carbon, and the second film may include a silicon-containing material such as amorphous silicon.
[0109] In step B, a third film 330 may be conformally formed on the second film 320 as an isolation film. The third film 330 may include a titanium-containing material, for example, by Figure 1 , Figure 2 , Figure 3A and Figure 3B When forming the third film 330, a variable frequency RF power may be applied to the reaction chamber, causing the third film to be amorphous.
[0110] In step C, the third film 330 formed in a direction perpendicular to the etching gas supplied toward the substrate may be selectively removed. In other words, a portion of the third film 330 formed on the top of the second film 320 and a portion of the third film 330 formed on the first film 310 between the second films 320 may be removed. This may result in equal thickness and spacing between the second film 320 and the third film 340 (i.e., a=b=c). Therefore, the third film 340 formed on the sidewall of the second film 320 may remain. In one embodiment, an etch-back process may be performed to selectively remove the third film 340.
[0111] In step D, the second film 320 (ie, the mandrel) may be selectively removed while the third film 340 remains intact. In one embodiment, a wet etching process may be performed to selectively remove the second film 320 .
[0112] In step E, the first film 310 (ie, the hard mask) may be further selectively removed while keeping the third film 340 intact. In one embodiment, a wet etching process may be performed to selectively remove the first film 310 .
[0113] In step F, the remaining third film 340 may be removed. This may result in the spacing between the remaining first films 310 being the same (ie, a=b=c). In one embodiment, an ashing or stripping process may be performed to remove the third film 340 .
[0114] The present disclosure may provide an additional technical benefit of improving process reproducibility between batches of substrates and between reaction chambers in a multi-reaction chamber system.
[0115] In a multi-chamber system, each reaction chamber can be connected to a power source (e.g., an RF power generator) and a matching network. For example, a first reaction chamber can be connected to a first power source and a first matching network, and a second reaction chamber can be connected to a second power source and a second matching network.
[0116] By supplying a source gas as a first gas, a reactant as a second gas, and a third gas containing hydrogen to the reaction chamber, a film can be formed on a substrate loaded in each reaction chamber. When the second gas and the third gas are supplied, power can be applied to each reaction chamber from each power source.
[0117] In a conventional multi-chamber system, impedance matching can be performed in a fixed frequency mode in each chamber. That is, the power frequency can be fixed, and the VVC can be moved to match the impedance between the power source and the chamber.
[0118] In fixed frequency mode, the mechanical and physical movement of the VVC may cause a matching time difference between the reaction chambers, resulting in low reproducibility of the process between the reaction chambers, such as Fig. 9A shown.
[0119] Fig. 9A The film thickness variation between batches and between reaction chambers in the same batch is shown in the fixed frequency mode. Fig. 9A In the embodiment of the present invention, 6 batches of substrates can be processed in the first reaction chamber and the second reaction chamber. A batch of substrates can include 25 substrates. The film can be a TiN film formed by the method of the present disclosure.
[0120] When comparing the film thickness differences between batches (i.e., from the first batch to the sixth batch), the film thickness difference can be about (For example, in the second batch, about In the sixth batch, about ). And the film thickness difference between reaction chambers in the same batch can be about to about in the range of (e.g., about In the second batch, about ).
[0121] In a multi-chamber system according to an embodiment of the present disclosure, impedance matching can be performed in a variable frequency mode in each reaction chamber. That is, when the position of the VVC in the matching network is fixed to match the impedance between the power source and the reaction chamber, the power frequency can be changed by firmware or an algorithm embedded in the power source.
[0122] Fig. 9B The film thickness differences between batches and between reaction chambers in the same batch are shown in variable frequency mode. Fig. 9B In the embodiment of the present invention, 6 batches of substrates can be processed in the first reaction chamber and the second reaction chamber. A batch of substrates can include 25 substrates. The film can be a TiN film formed by the method of the present disclosure.
[0123] When comparing the film thickness differences between batches (i.e., from the first batch to the sixth batch), the film thickness differences can be less than about (For example, in the second batch, about In the third batch, about ), which is lower than the fixed frequency mode. And the film thickness difference between reaction chambers in the same batch can be less than about (For example, in the second batch, about In the third batch, about ), which is lower than the fixed frequency mode. That is, fast matching can reduce the matching time difference between reaction chambers, thereby improving the reproducibility of the process between batches and between reaction chambers.
[0124] Fig.10 A multiple reaction chamber system 10 according to the present disclosure is shown.
[0125] exist Fig.10 In the embodiment, the multi-reaction chamber system 10 may include a reaction chamber unit 20 for processing a substrate, a gas supply unit 30 for supplying a gas to the reaction chamber unit 20 , and a power supply unit 40 for applying power to the reaction chamber unit 20 .
[0126] The reaction chamber unit 20 may include a plurality of reaction chambers (ie, a first reaction chamber RC1 and a second reaction chamber RC2). However, the number of reaction chambers is not limited thereto. In other embodiments, the reaction chamber unit 20 may further include a third reaction chamber and a fourth reaction chamber (not shown here).
[0127] The gas supply unit 30 may include a first gas supply unit G1 that supplies gas to the first reaction chamber RC1 and a second gas supply unit G2 that supplies gas to the second reaction chamber RC2.
[0128] The power supply unit 40 may include a power source 50 (e.g., an RF power generator) generating power and a matching network 60 matching impedance between the power source 50 and the reaction chamber unit 20. The power source 50 may include a first power source P1 applying power to the first reaction chamber RC1 and a second power source P2 applying power to the second reaction chamber RC2.
[0129] The matching network 60 may include a first matching network M1 matching the impedance between the first power source P1 and the first reaction chamber RC1, and a second matching network M2 matching the impedance between the second power source P2 and the second reaction chamber RC2.
[0130] The power source 50 may be provided with firmware or an algorithm to vary the frequency of the power.
[0131] The matching network 60 may include a VVC (vacuum variable capacitor). The VVC may be mechanically moved to find the best matching position.
[0132] In one embodiment according to the present disclosure, a first gas as a source gas and a second gas as a reactant may be supplied to the reaction chamber unit 20 to form a film on a substrate. The second gas may be activated by power applied to the reaction chamber. When power is applied, matching may be performed between the power source 50 and the reaction chamber unit 20 by changing the frequency of the power by firmware embedded in the power source without moving the VVC in the matching network 60.
[0133] It should be understood that the configuration and / or method described herein are exemplary in nature, and these specific embodiments or examples should not be considered restrictive, because many variations are possible. The specific routine or method described herein can represent one or more of any number of processing strategies. Therefore, the various actions shown can be performed in the order shown, in other orders, or omitted in some cases.
[0134] The subject matter of the present disclosure includes all novel and nonobvious combinations and subcombinations of the various processes, systems and configurations, and other features, functions, acts and / or properties disclosed herein, and any and all equivalents thereof.
Claims
1. A method for forming a film on a patterned substrate, the method comprising: providing a patterned substrate to a reaction chamber; supplying a first gas to the reaction chamber; supplying a second gas to the reaction chamber; as well as Applying power to the reaction chamber, where the power has a variable frequency, wherein the second gas is activated by power, and Therein, the activated second gas reacts with the first gas to form a film on the patterned substrate.
2. The method according to claim 1, wherein: The film includes amorphous titanium nitride.
3. The method according to claim 2, wherein: The amorphous titanium nitride film also contains impurities at a level of 25% or less.
4. The method according to claim 3, wherein: The impurities include at least one of oxygen, carbon or a mixture thereof.
5. The method according to claim 2, wherein: The membrane is a separator membrane.
6. The method according to claim 1, wherein: A reflected power of 5 W or less is generated during application of power to the reaction chamber.
7. The method according to claim 1, wherein: The first gas includes a titanium-containing gas.
8. The method according to claim 7, wherein: The first gas includes at least one of the following: tetrakisdimethylamidotitanium (Ti[N(CH3)2]4, TDMAT), tetrakisdiethylamidotitanium ([(C2H5)2N]4Ti, TDEAT), tetraethylmethylamidotitanium (Ti[(CH3C2H5)N]4, TEMAT), titanium isopropoxide (Ti[OCH(CH3)2], TTIP), titanium chloride (TiCl4), derivatives thereof or mixtures thereof.
9. The method according to claim 1, wherein: The second gas includes a nitrogen-containing gas.
10. The method according to claim 9, wherein: The second gas includes at least one of the following: N2, NH3, NH4, N2H2, N2H4 or a mixture thereof. 11 . The method of claim 1 , further comprising supplying a third gas to the reaction chamber, and simultaneously activating the second gas and the third gas by the power.
12. The method according to claim 11, wherein: The method is repeated multiple times.
13. The method of claim 1, further comprising processing a film by supplying a third gas to the reaction chamber and activating the third gas by the power after forming the film, wherein a frequency of the power is a variable frequency.
14. The method according to claim 13, wherein treating the film and forming the film are respectively repeated a plurality of times, and a super cycle including treating the film and forming the film is repeated a plurality of times.
15. The method according to any one of claims 11 to 14, wherein: The third gas includes a hydrogen-containing gas.
16. The method according to claim 15, wherein: The third gas includes at least one of hydrogen gas, atomic hydrogen, or a mixture thereof.
17. The method according to any one of claims 1 to 14, wherein: The method of forming the film is performed between about 100°C and about 250°C or between about 150°C and about 200°C.
18. The method according to any one of claims 1 to 14, wherein: A power of between about 200 W and about 500 W or between about 250 W and about 450 W is applied to the reaction chamber.
19. A method for patterning a substrate, the method comprising: providing a substrate to a reaction chamber; forming a first film on a substrate; forming a second film on the first film; patterning the second film; forming a third film on the second film; selectively removing the third membrane; removing the second film; selectively removing the first film; as well as The third film is removed, wherein the first film includes a carbon-containing material, the second film includes a silicon-containing material, and the third film includes a titanium-containing material.
20. The method according to claim 19, wherein: The first film includes amorphous carbon, and the second film includes amorphous silicon.
21. The method according to claim 19, wherein: The third film is selectively removed by etching back.
22. The method according to claim 19, wherein: Selectively removing the second film and removing the first film are performed by selective etching.
23. The method according to claim 19, wherein: Removing the third film is performed by at least one of ashing or stripping.
24. The method according to claim 19, wherein: The third film includes amorphous titanium nitride.
25. The method of claim 19, wherein: Forming the third film on the second film is performed by the method according to claim 1 .
26. An apparatus for executing the method according to claim 1, comprising: a reaction chamber unit for processing a substrate; a gas supply unit for supplying a first gas as a source gas and a second gas as a reactant to the reaction chamber unit to form a film on the substrate; as well as a power supply unit including a power source and a matching network to apply power to the reaction chamber unit, The second gas is activated by power applied to the reaction chamber unit, and matching is performed between the power source and the reaction chamber unit by changing the frequency of the power while applying the power to the reaction chamber unit.