Fluorine-doped atomic layer deposition method

Abstract

The invention discloses a fluorine-doped atomic layer deposition method, which is used for depositing a fluorine-containing oxide film layer on a wafer. The method comprises the following steps: determining the thickness of an oxide film layer and m components in the oxide film layer, wherein each component corresponds to a sub-cycle; based on the component proportion in the oxide film layer, determining the cycle index and process of each component corresponding to the sub-cycle; the process of the sub-cycle comprises fluorine-containing treatment and fluorine-free treatment; judging whether the process of the current sub-cycle is fluorine-containing treatment or not, and if yes, introducing fluorine-containing gas or fluorine-containing plasma gas in the process of executing the current sub-cycle; a hypercycle is formed after the cycle times of all group molecular cycles are completed; and based on the thickness of the oxide film layer, the hypercycle is repeatedly executed until the thickness of the oxide film layer is reached. According to the method, the fluorine-containing gas or plasma is introduced in the atomic layer deposition circulation, additional process steps are not needed, the whole process flow time can be shortened, and the process steps are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of atomic layer deposition, and more specifically, to a fluorine-doped atomic layer deposition method. Background Art

[0002] Over the past decade, atomic layer deposition (ALD) has become a key thin-film deposition technology in fields such as nanoelectronics and catalysis due to its excellent conformality on three-dimensional nanostructured substrates and the ability to control film thickness at the atomic level.

[0003] F doping can improve the performance of some functional oxide films such as SnO 2 , or containing SnO 2 The stability of ternary compounds such as ITO, ATO, and ZTO films. The doping process or deposited multi-element materials using conventional atomic layer deposition are mostly oxides or nitrides, and the doping materials are mostly metal materials or N, O, and H, all using the same reaction gas (reactant). It is difficult to dope the highly oxidizing element F in this way.

[0004] In the prior art, the deposited functional oxide film is doped with F, generally by ion implantation, high temperature diffusion, or long-term plasma treatment. These methods have the following main problems: additional process steps are required; annealing may be required to introduce high temperature processes; doping (ion implantation, thermal diffusion) and plasma treatment methods will damage the functional oxide film; and it is difficult to quantify the amount of fluorine in plasma treatment. Summary of the invention

[0005] In view of this, an object of the present invention is to provide a fluorine-doped atomic layer deposition method to solve the problems existing in the prior art.

[0006] To achieve the above object, the technical solution of the present invention is as follows: A fluorine-doped atomic layer deposition method is used to deposit an oxide film layer containing fluorine on a wafer; the method comprises: Determine the thickness of the oxide film layer and m components in the oxide film layer, each component corresponds to a sub-cycle; m is a positive integer; Based on the component ratio in the oxide film layer, determining the number of cycles and the process of the sub-cycle corresponding to each component; the sub-cycle process includes fluorine-containing treatment and fluorine-free treatment; Determine whether the process of the current sub-cycle is a fluorine-containing process, and if so, introduce a fluorine-containing gas or a fluorine-containing plasma gas into the process of executing the current sub-cycle; After the number of cycles of all component sub-cycles is completed, a super-cycle is formed; Based on the thickness of the oxide film layer, the super cycle is repeatedly performed until the thickness of the oxide film layer is reached.

[0007] Furthermore, when the process of the corresponding sub-cycle is fluorine-free treatment, it includes: The precursor of the corresponding component is introduced so that the precursor of the corresponding component is adsorbed on the surface of the wafer; Introducing purge gas to purge excess precursor in the chamber; The reaction gas of the corresponding component is introduced to react with the precursor adsorbed on the surface of the wafer to form a film of the corresponding component with a certain thickness; A purge gas is introduced to purge out excess reaction gas in the chamber.

[0008] Furthermore, when the process of the current sub-cycle is fluorine-containing treatment: After the reaction gas of the corresponding component is introduced, the fluorine-containing gas or fluorine-containing plasma gas is introduced, and then the purge gas is introduced; Alternatively, before the reaction gas of the corresponding component is introduced, the fluorine-containing gas or the fluorine-containing plasma gas is introduced; Alternatively, while introducing the reaction gas of the corresponding component, the fluorine-containing gas or the fluorine-containing plasma gas is introduced; Alternatively, after the precursor of the corresponding component is introduced, the fluorine-containing gas or fluorine-containing plasma gas is introduced, and then the purge gas is introduced; Alternatively, before the precursor of the corresponding component is introduced, a fluorine-containing gas or a fluorine-containing plasma gas is introduced. Alternatively, the fluorine-containing gas or fluorine-containing plasma gas is introduced while the precursor of the corresponding component is introduced.

[0009] Furthermore, the fluorine-containing gas or the gas capable of generating fluorine-containing plasma comprises CF 4 , CHF 3 , C 2 F 6 , SF 6 Any one or more of .

[0010] Furthermore, the flow rate of the fluorine-containing gas or fluorine-containing plasma gas is 10 sccm-100 sccm, preferably 20 sccm.

[0011] Furthermore, if the fluorine-containing gas is introduced, the chamber is subjected to high-frequency electric field treatment, and the power of the radio frequency power source is set to 30W-80W, preferably 50W during the high-frequency electric field treatment.

[0012] Furthermore, when the number of components in the oxide film layer is 1, it includes: First, perform A sub-cycle of fluorine-free treatment, and then perform B sub-cycles of fluorine-containing treatment. If the thickness of the oxide film layer is not reached, continue to perform A sub-cycle of fluorine-free treatment, and perform B sub-cycles of fluorine-containing treatment until the thickness of the oxide film layer is reached; Alternatively, the fluorine-containing treatment is performed in all sub-cycles until the thickness of the oxide film layer is reached; Alternatively, the first 1-2 times of the sub-cycle are treated with fluorine, and then the remaining times are treated with fluorine-free treatment until the thickness is reached, and then 1-2 more times of fluorine treatment are performed; Wherein, A and B are both natural numbers greater than or equal to 1.

[0013] Further, when the oxide film layer includes a first component and a second component; Includes fluoride treatment in every supercycle; or fluorine treatment in part of the supercycle; Among them, the fluorine treatment in the super cycle includes: The fluorine-containing treatment is performed in all sub-cycles of the first component or in part of the sub-cycles; Alternatively, the fluorine-containing treatment is carried out in all sub-cycles of the second component or in part of the sub-cycles.

[0014] Compared with the prior art, the present invention has the following advantages: The present invention introduces fluorine-containing gas or plasma during the atomic layer deposition cycle to achieve interface fluorine treatment, doping, and passivation as the film deposition is completed, thereby improving the reliability of the functional oxide film. No additional process steps are required, which can reduce the time of the entire process flow, reduce process steps, and reduce the risk of yield loss. Additional high-temperature processes can be avoided without damaging the film layer. The fluorine-containing gas flow rate can be controlled by a gas mass flowmeter to accurately control the amount of fluorine added, thereby improving the stability of the film layer without reducing other properties of the film layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 In the embodiment of the present invention, SnO is deposited 2 Taking the film layer as an example, different process flows corresponding to the sub-cycle of fluorine-containing treatment are performed; wherein A) is to introduce fluorine-containing gas or fluorine-containing plasma gas in one step after introducing the reaction gas; B) is to introduce fluorine-containing gas or fluorine-containing plasma gas in one step before introducing the reaction gas; C) is to introduce fluorine-containing gas or fluorine-containing plasma gas while introducing the reaction gas; D) is to introduce fluorine-containing gas or fluorine-containing plasma gas in one step after introducing the Sn precursor; E) is to introduce fluorine-containing gas or fluorine-containing plasma gas in one step before introducing the Sn precursor; F) is to introduce fluorine-containing gas or fluorine-containing plasma gas while introducing the Sn precursor.

[0016] Figure 2 The SnO deposited in the embodiment of the present invention 2 Taking the SnO film layer as an example, different combination processes of sub-cycles without fluorine treatment and sub-cycles with fluorine treatment; A) is a SnO 2 cycle; B) SnO treated with fluorine 2 cycle; C) is in SnO 2 1-2 atomic layers of fluorinated SnO deposited on the bottom and / or top of the film 2 cycle. DETAILED DESCRIPTION

[0017] Embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as being limited to the embodiments described herein, which are instead provided for a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0018] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. In addition, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0019] The term "including" and its variations used in this document are open inclusions, that is, "including but not limited to". The term "based on" means "based at least in part on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments". Relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first", "second", etc. mentioned in the present invention are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0020] It should be noted that the modifications of "one" and "plurality" mentioned in the present invention are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0021] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0022] Unless otherwise specified, the materials and reagents used in the present invention can be obtained from commercial products in the art.

[0023] It should be noted that atomic layer deposition has the advantages of sub-nanometer precision thick film control, good conformality of complex structures, high step coverage, and excellent uniformity. Functional oxide films deposited with atomic layer deposition are suitable for advanced semiconductor processes. Fluorine passivation and doping of functional oxide films can improve film stability. However, conventional atomic layer deposition doping processes cannot achieve F doping.

[0024] Based on this, an embodiment of the present invention provides a fluorine-doped atomic layer deposition method for depositing an oxide film layer containing fluorine on a wafer; The method comprises the following steps S1-S5: S1, determine the thickness of the oxide film layer and the m components in the oxide film layer, each component corresponds to a sub-cycle; m is a positive integer; Optionally, the oxide film layer is generally a metal oxide film layer; When m is 1, the corresponding deposited oxide film contains only one component, such as the common SnO 2 ; When m is 2, the corresponding deposited oxide film contains two metal oxides, i.e., two components, the common ones include SnO 2 Ternary films such as ITO (indium tin oxide), ATO (antimony-doped tin dioxide), ZTO (zinc stannate), etc.

[0025] Among them, ITO is an N-type oxide semiconductor with a chemical formula of In 2 O 3 :SnO 2 , usually composed of 90% indium oxide (In 2 O 3 ) and 10% tin oxide (SnO 2 ) is composed of; ATO is an N-type semiconductor material, which is mainly composed of tin oxide and antimony oxide. 2 :Sb 2 O 3 =90:10 or SnO 2 :Sb 2 O3 =95:5 is a common ratio; ZTO is a ternary oxide semiconductor material with a chemical formula of Zn 2 SnO 4 .

[0026] Of course, optionally, m can also be 3 or above, that is, quaternary compounds, quinary compounds, etc. can be deposited, and the selection is made according to actual needs.

[0027] S2, based on the component ratio in the oxide film layer, determining the number of cycles and the process of the sub-cycle corresponding to each component; the sub-cycle process includes a fluorine-containing treatment and a fluorine-free treatment; Optionally, when there is only one component in the oxide film layer, the number of cycles can be directly determined according to the thickness of the oxide film layer; when there are more than two components in the oxide film layer, the number of cycles corresponding to each component can be determined according to the ratio between the components. For example, when depositing SnO 2 When the ternary thin film ITO is used, if In 2 O 3 :SnO 2 The ratio is 9:1, and it can be preliminarily determined that the sub-cycle of In is set to 9 times, and the sub-cycle of Sn is set to 1 time. Optionally, the sub-cycle of In can be set to 18 times, and the sub-cycle of Sn can be set to 2 times; or if In 2 O 3 :SnO 2 The ratio is 5:3, and it can be preliminarily determined that the In sub-cycle is set to 5 times, and the Sn sub-cycle is set to 3 times. Optionally, the In sub-cycle can be set to 10 times, and the Sn sub-cycle can be set to 6 times; that is, the number of cycles of each sub-cycle can be determined according to the component ratio of the oxide film layer to be deposited.

[0028] After determining the number of cycles of each sub-cycle, the deposition process of each sub-cycle can be determined as needed; the sub-cycle process includes fluorine-containing treatment and fluorine-free treatment, and the fluorine-free treatment is the conventional treatment; the fluorine-containing treatment means that when the current cycle process is carried out, fluorine-containing gas or plasma is introduced to achieve fluorination treatment of the film layer to achieve F element doping.

[0029] Specifically, when the process of the corresponding sub-cycle is fluorine-free treatment, the following steps are included: S221, introducing the precursor of the corresponding component so that the precursor of the corresponding component is adsorbed on the surface of the wafer; S222, introducing a purge gas to purge excess precursor in the chamber; S223, introducing a reaction gas of a corresponding component to react with the precursor adsorbed on the surface of the wafer to form a film of the corresponding component with a certain thickness; S224, introducing a purge gas to purge out excess reaction gas in the chamber.

[0030] Optionally, the purge gas may be nitrogen or an inert gas.

[0031] S3, determining whether the process of the current sub-cycle is a fluorine-containing treatment, and if so, introducing a fluorine-containing gas or a fluorine-containing plasma gas into the process of executing the current sub-cycle; That is, when it is determined that the process of the current sub-cycle is fluorine-containing treatment: That is, after the reaction gas of the corresponding component is introduced, the fluorine-containing gas or fluorine-containing plasma gas is introduced, and then the purge gas is introduced; Alternatively, before the reaction gas of the corresponding component is introduced, the fluorine-containing gas or the fluorine-containing plasma gas is introduced; Alternatively, while introducing the reaction gas of the corresponding component, the fluorine-containing gas or the fluorine-containing plasma gas is introduced; Alternatively, after the precursor of the corresponding component is introduced, the fluorine-containing gas or fluorine-containing plasma gas is introduced, and then the purge gas is introduced; Alternatively, before the precursor of the corresponding component is introduced, a fluorine-containing gas or a fluorine-containing plasma gas is introduced. Alternatively, the fluorine-containing gas or fluorine-containing plasma gas is introduced while the precursor of the corresponding component is introduced.

[0032] like Figure 1 As shown, SnO is deposited 2 Taking the film layer as an example, when it is determined that the process of the current sub-cycle is fluorine-containing treatment, the flow chart shows that the fluorine-containing gas or fluorine-containing plasma gas can be introduced before, after or at the same time as the reaction gas; the fluorine-containing gas or fluorine-containing plasma gas can be introduced before, after or at the same time as the Sn precursor; wherein, preferably, the fluorine-containing gas or fluorine-containing plasma gas is introduced one step after the precursor of the corresponding component is introduced (that is, after the Sn precursor is introduced), and then the purge gas is introduced, so that the formed film layer effect is better.

[0033] S4, after the number of cycles of all component sub-cycles is completed, a super-cycle is formed; S5, based on the thickness of the oxide film layer, repeatedly performing the super cycle until the thickness of the oxide film layer is reached.

[0034] It can be understood that when the oxide film layer has only one component, completing one sub-cycle is equivalent to one super-cycle.

[0035] When the oxide film layer has two components, including a first component and a second component, assuming that the number of sub-cycles of the first component is set to 5 times and the number of sub-cycles of the second component is set to 3 times, then after the 5 sub-cycles of the first component and the 3 sub-cycles of the second component are completed, it is equivalent to completing a super cycle; at this time, a film layer of a certain thickness is formed, and the super cycle is repeated until the required film layer thickness is reached.

[0036] Optionally, before deposition, pre-calibration is generally performed, that is, according to the same deposition process, a certain number of process deposition cycles are performed for the first component, such as 100 cycles, and then the film thickness obtained after 100 cycles is measured as H, then H / 100 is the film thickness that can be obtained by the first component after an average cycle.

[0037] Similarly, for the second component, calibration can also be performed before atomic layer deposition, and then the corresponding film thickness value after an average cycle deposition is obtained.

[0038] After each component is calibrated, the corresponding film thickness value that can be deposited after each super cycle can be obtained, so that the total number of super cycles required can be preliminarily calculated.

[0039] Optionally, the fluorine-containing gas or the fluorine-containing plasma gas comprises CF 4 , CHF 3 , C 2 F 6 , SF 6 Any one or more of .

[0040] Optionally, the flow rate of the fluorine-containing gas or fluorine-containing plasma gas is 10sccm-100sccm. It should be noted that, through appropriate flow control, on the one hand, the amount of fluorine element doping can be accurately controlled, and at the same time, the etching problem caused by fluorine can be avoided. The present invention has found in experiments that if the flow rate of the fluorine-containing gas or fluorine-containing plasma gas is too low, the fluorine element is difficult to be effectively doped. If the flow rate of the fluorine-containing gas or fluorine-containing plasma gas is too high, it is easy to cause etching problems caused by fluorine, affecting the performance of the final product. In some embodiments, the flow rate of the fluorine-containing gas or fluorine-containing plasma gas is preferably 20sccm, which can achieve optimal doping while completely avoiding etching.

[0041] Optionally, the corresponding plasma can be directly generated by using a fluorine-containing gas through an auxiliary device, and then introduced into the chamber for fluorine-containing treatment; Of course, fluorine-containing gas can also be directly introduced. Compared with directly introducing fluorine-containing plasma gas, the deposition efficiency of introducing fluorine-containing gas is a little lower; at this time, the chamber can also be further subjected to high-frequency electric field treatment to improve its reaction efficiency; the RF power supply power is set to 30W-80W. Similarly, this embodiment sets the RF power supply power to 30W-80W, which can better achieve the incorporation of fluorine elements on the one hand, and also avoid the etching problem caused by fluorine. In some embodiments, the RF power supply power is preferably set to 50W.

[0042] Optionally, in some embodiments, when the number of components in the oxide film layer is 1, it includes: First, perform A sub-cycle of fluorine-free treatment, and then perform B sub-cycles of fluorine-containing treatment. If the thickness of the oxide film layer is not reached, continue to perform A sub-cycle of fluorine-free treatment, and perform B sub-cycles of fluorine-containing treatment until the thickness of the oxide film layer is reached; Alternatively, the fluorine-containing treatment is performed in all sub-cycles until the thickness of the oxide film layer is reached; Alternatively, the first 1-2 times of the sub-cycle are treated with fluorine, and then the remaining times are treated with fluorine-free treatment until the thickness is reached, and then 1-2 more times of fluorine treatment are performed; Wherein, A and B are both natural numbers greater than or equal to 1.

[0043] like Figure 2 As shown, SnO 2 As an example, the entire film layer can be composed of SnO 2 Atomic layer cycle composition ( Figure 2 A), A and B are natural numbers greater than or equal to 1, or all are fluorine-treated SnO 2 Cycle composition ( Figure 2 B), or in SnO 2 1-2 atomic layers of fluorinated SnO are deposited on the bottom or top of the film 2 ( Figure 2 C). Further, when the oxide film layer includes the first component and the second component, it may include: Fluoride treatment was performed in each supercycle; or fluorine treatment in part of the supercycle; Among them, the fluorine-containing treatment in the super cycle includes: The fluorine-containing treatment is performed in all sub-cycles of the first component or in part of the sub-cycles; Alternatively, the fluorine-containing treatment is carried out in all sub-cycles of the second component or in part of the sub-cycles.

[0044] Optionally, when the oxide film layer includes a first component, a second component and a third component, it may include: Fluoride treatment was performed in each supercycle; or fluorine treatment in part of the supercycle; Among them, the fluorine-containing treatment in the super cycle includes: The fluorine-containing treatment is performed in all sub-cycles of the first component or in part of the sub-cycles; Alternatively, the fluorine-containing treatment is performed in all sub-cycles of the second component or in part of the sub-cycles; Alternatively, the fluorine-containing treatment is carried out in all sub-cycles of the third component or in part of the sub-cycles.

[0045] Taking ITO as an example, the supercycle of ITO deposition includes SnO 2 Sub-loop and In 2 O 3 The fluorine treatment can be performed in every ITO supercycle or in part of the supercycle. 2 The sub-cycles can all be fluorinated or part of the cycle can be fluorinated. In some cases, the In in the super-cycle of the fluorinated ITO can be 2 O 3 The fluorine treatment can be performed in a sub-cycle. The fluorine treatment can also be performed on the upper interface or the lower interface of the ITO thin layer.

[0046] In summary, this patent improves the reliability of the functional oxide film by introducing fluorine-containing gas or plasma into the atomic layer deposition cycle, and realizes interface fluorine treatment, doping, and passivation as the film deposition is completed. No additional process steps are required, which reduces the time of the entire process flow, reduces the process steps, and reduces the risk of yield loss; avoids additional high-temperature processes and does not damage the film layer; the fluorine-containing gas flow rate can be controlled by a gas mass flowmeter to accurately control the amount of fluorine added, thereby improving the stability of the film layer without reducing other properties of the film layer.

[0047] The following is an explanation of the specific implementation process: Preparation of ITO sample 1: temperature 250 ℃, SnO 2 cycle: TDMASn carrier gas flow rate 250 sccm, pulse 3 s, with 450 sccm N 2 Purge 12 s, O 2 Flow rate 150 sccm, RF power 300 W, pulse 8 s, CF 4The flow rate was 20 sccm, the RF power was 50 W, the pulse was 1 s, and 450 sccm of N 2 Purge for 12 s.

[0048] In 2 O 3 Cycle: DADI carrier gas flow rate 250 sccm, pulse 3 s, 450 sccm N 2 Purge 12 s, O 2 The flow rate was 150 sccm, the RF power was 300 W, the pulse was 8 s, and 450 sccm of N 2 Purge for 12 s.

[0049] ITO cycle: 1 ITO cycle is 5 times of SnO 2 cycle, and then perform 3 more In 2 O 3 cycle, and ITO cycle was repeated 10 times.

[0050] That is, a fluorine-doped ITO film layer with a thickness of 7.1 nm was prepared.

[0051] Preparation of ITO sample 2: temperature 250 ℃, SnO 2 cycle: TDMASn carrier gas flow rate 250 sccm, pulse 3 s, with 450 sccm N 2 Purge 12 s, O 2 Flow rate 150 sccm, RF power 300 W, pulse 8 s, CF 4 The flow rate was 5 sccm, the RF power was 50 W, the pulse was 1 s, and 450 sccm of N 2 Purge for 12 s.

[0052] In 2 O 3 Cycle: DADI carrier gas flow rate 250 sccm, pulse 3 s, 450 sccm N 2 Purge 12 s, O 2 The flow rate was 150 sccm, the RF power was 300 W, the pulse was 8 s, and 450 sccm of N 2 Purge for 12 s.

[0053] ITO cycle: 1 ITO cycle is 5 times of SnO 2 cycle, and then perform 3 more In 2 O 3 cycle, and ITO cycle was repeated 10 times.

[0054] That is, a fluorine-doped ITO film layer with a thickness of 7 nm is prepared.

[0055] Preparation of ITO sample 3: temperature 250 ℃, SnO 2 cycle: TDMASn carrier gas flow rate 250 sccm, pulse 3 s, with 450 sccm N 2 Purge 12 s, O 2 The flow rate was 150 sccm, the RF power was 300 W, the pulse was 8 s, and the N2 purge was 450 sccm for 12 s.

[0056] In 2 O 3 Cycle: DADI carrier gas flow rate 250 sccm, pulse 3 s, 450 sccm N 2 Purge 12 s, O 2 The flow rate was 150 sccm, the RF power was 300 W, the pulse was 8 s, and 450 sccm of N 2 Purge for 12 s.

[0057] ITO cycle: 1 ITO cycle is 5 times of SnO 2 cycle, and then perform 3 more In 2 O 3 cycle, and ITO cycle was repeated 10 times.

[0058] That is, an ITO film layer with a thickness of 7.1 nm was prepared.

[0059] SIMS test was performed on samples 1-3, and the test results were as follows: the fluorine intensity of sample 1 was 2E3, the intensity of sample 2 was 1E2, and the intensity of sample 3 was 2E1, indicating that the doping of F element was successfully achieved in samples 1 and 2, and sample 1 had a higher F element content than samples 2 and 3. It is proved that the atomic layer deposition method for doping fluorine element provided by the present invention can successfully achieve stable F element doping.

[0060] The devices made from samples 1-3 were subjected to thermal stability tests, and the results are shown in the following table:

[0061] As can be seen from the above table, the devices made from samples 2 and 3 have large drift and dispersion in Vt after annealing, indicating that the thermal stability of the film is poor, while the devices made from sample 1 have better thermal stability.

[0062] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0063] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for atomic layer deposition doped with fluorine, characterized in that: Used to deposit an oxide film layer containing fluorine elements on a wafer; the method comprises: Determine the thickness of the oxide film layer and m components in the oxide film layer, each component corresponds to a sub-cycle; m is a positive integer; Based on the component ratio in the oxide film layer, determining the number of cycles and the process of the sub-cycle corresponding to each component; the sub-cycle process includes fluorine-containing treatment and fluorine-free treatment; Determine whether the process of the current sub-cycle is a fluorine-containing process, and if so, introduce a fluorine-containing gas or a fluorine-containing plasma gas into the process of executing the current sub-cycle; After the number of cycles of all component sub-cycles is completed, a super-cycle is formed; Based on the thickness of the oxide film layer, the super cycle is repeatedly performed until the thickness of the oxide film layer is reached.

2. The fluorine-doped atomic layer deposition method according to claim 1, characterized in that: When the process of the corresponding sub-cycle is fluorine-free treatment, it includes: The precursor of the corresponding component is introduced so that the precursor of the corresponding component is adsorbed on the surface of the wafer; Introducing purge gas to purge excess precursor in the chamber; The reaction gas of the corresponding component is introduced to react with the precursor adsorbed on the surface of the wafer to form a film of the corresponding component with a certain thickness; A purge gas is introduced to purge out excess reaction gas in the chamber.

3. The fluorine-doped atomic layer deposition method according to claim 2, characterized in that: When the process of the current sub-cycle is fluorine-containing treatment: After the reaction gas of the corresponding component is introduced, the fluorine-containing gas or fluorine-containing plasma gas is introduced, and then the purge gas is introduced; Alternatively, before the reaction gas of the corresponding component is introduced, the fluorine-containing gas or the fluorine-containing plasma gas is introduced; Alternatively, while introducing the reaction gas of the corresponding component, the fluorine-containing gas or the fluorine-containing plasma gas is introduced; Alternatively, after the precursor of the corresponding component is introduced, the fluorine-containing gas or fluorine-containing plasma gas is introduced, and then the purge gas is introduced; Alternatively, before the precursor of the corresponding component is introduced, a fluorine-containing gas or a fluorine-containing plasma gas is introduced. Alternatively, the fluorine-containing gas or fluorine-containing plasma gas is introduced while the precursor of the corresponding component is introduced.

4. The fluorine-doped atomic layer deposition method according to claim 1, characterized in that: The fluorine-containing gas or the gas capable of generating fluorine-containing plasma includes any one or more of CF4, CHF3, C2F6, and SF6.

5. The fluorine-doped atomic layer deposition method according to claim 1, characterized in that: The flow rate of the fluorine-containing gas or fluorine-containing plasma gas is 10 sccm-100 sccm.

6. The fluorine-doped atomic layer deposition method according to claim 1, characterized in that: If fluorine-containing gas is introduced, the chamber is also subjected to high-frequency electric field treatment, and the power of the radio frequency power supply is set to 30W-80W during the high-frequency electric field treatment.

7. The fluorine-doped atomic layer deposition method according to claim 1, characterized in that: When the number of components in the oxide film layer is 1, it includes: First, perform A sub-cycle of fluorine-free treatment, and then perform B sub-cycles of fluorine-containing treatment. If the thickness of the oxide film layer is not reached, continue to perform A sub-cycle of fluorine-free treatment, and perform B sub-cycles of fluorine-containing treatment until the thickness of the oxide film layer is reached; Alternatively, the fluorine-containing treatment is performed in all sub-cycles until the thickness of the oxide film layer is reached; Alternatively, the first 1-2 times of the sub-cycle are treated with fluorine, and then the remaining times are treated with fluorine-free treatment until the thickness is reached, and then 1-2 more times of fluorine treatment are performed; Wherein, A and B are both natural numbers greater than or equal to 1.

8. The fluorine-doped atomic layer deposition method according to claim 1, characterized in that: When the oxide film layer includes a first component and a second component; Includes fluoride treatment in every supercycle; or fluorine treatment in part of the supercycle; Among them, the fluorine treatment in the super cycle includes: The fluorine-containing treatment is performed in all sub-cycles of the first component or in part of the sub-cycles; Alternatively, the fluorine-containing treatment is carried out in all sub-cycles of the second component or in part of the sub-cycles.

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