Deposition gas

Abstract

To provide a deposition gas containing hydrofluoroethylene, and a method for performing plasma-processed deposition using the deposition gas.SOLUTION: A deposition gas used for depositing materials onto semiconductor substrates during semiconductor manufacturing, contains fluoroethylene, from the perspective of deposition rate (DR), preferably 1 vol% to 99 vol%, more preferably 10 vol% to 90 vol% with respect to the deposition gas total volume set at 100 vol%.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to deposition gases. [Background technology]

[0002] Patent Document 1 discloses a plasma processing gas that is a mixed gas of C4F8 and 2,3,3,3-tetrafluoropropene. [Prior art documents] [Non-patent literature]

[0003] [Patent Document 1] International Publication No. WO2022 / 074708A1 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure aims to provide a novel deposition gas containing hydrofluoroethylene. [Means for solving the problem]

[0005] The present disclosure encompasses the following configurations.

[0006] Section 1. Deposition gas containing hydrofluoroethylene.

[0007] Section 2. Item 2. The deposition gas according to item 1, wherein the hydrofluoroethylene is difluoroethylene.

[0008] Section 3. Item 1, wherein the deposition gas is for deposition in a plasma process in the manufacture of a substrate having a through-silicon via (TSV).

[0009] Section 4. Item 1, wherein the deposition gas is for deposition in a Bosch process in the manufacture of a substrate having a through-silicon via (TSV).

[0010] Section 5. A method for depositing on a substrate for manufacturing a semiconductor, using the deposition gas according to item 1.

[0011] Section 6. the substrate is a substrate including a through silicon via (TSV), 6. The method according to claim 5, wherein the deposition gas according to claim 1 is used for plasma treatment deposition.

[0012] Section 7. the substrate is a substrate including a through silicon via (TSV), In the Bosch process, Deposition is performed using the deposition gas described in item 1. The method according to item 5.

[0013] Section 8. A method of depositing a semiconductor on a substrate for manufacturing, comprising: Using the deposition gas described in Item 1, The method includes adjusting the deposition rate (DR) under the condition that the following formula is satisfied: (1) Source power area density: W / cm 2 At the time Deposition rate (DR)=-6.8*10 14 *x 2 +1.5*10 9 *x (2) Volume density of source power: W / cm 3 At the time Deposition rate (DR)=-6.6*10 19 *x 2 +4.7*10 11 *x x = (relative intensity of deposition gas) * (square of source power density) Relative intensity: The relative intensity is calculated by dividing the radical intensity of the desired m / z measured using a quadrupole mass spectrometer (QMS) by the sum of the radical intensities of mass numbers in the range of 1≦m / z≦150 (2.5 times the molecular weight of the deposition gas). Radical intensity: (measured intensity of each mass number (m / z)) * (√m) The radical intensity is calculated by multiplying the measured intensity of each mass number (m / z) by √m, and this corrects for the mass dependency of the measurement sensitivity of the QMS. m: molecular weight z: Charge ionized in QMS Source Power Density: Source power: Inductively coupled plasma (ICP) power during deposition (unit: W) (1) Source power area density (unit: W / cm 2 ) (2) Source power volume density (unit: W / cm 3 ) Relative intensity of CH2=CF2 (m / z=64)*(square of source power density) (1) Area of ​​the dielectric window where plasma is generated: 2,640 cm 2 (2) Volume of the plasma generation region: 46,600 cm 3

[0014] Section 9. In the above formula, x=(relative intensity of deposition gas)*(square of source power density), The range of x is The source power density is defined as (1) the source power area density (unit: W / cm 2 ), 4.0*10 -7 ≦ x ≦ 2.0*10 -6 or (2) Source power density (unit: W / cm 3 ), 1.3*10 -9 ≦ x ≦ 6.0*10 -9 Item 9. The method according to Item 8, wherein

[0015] Section 10. Item 1. A semiconductor manufacturing apparatus having the gas ejection part for deposition gas according to item 1.

[0016] Section 11. A method for producing a semiconductor, comprising depositing a semiconductor on a substrate using the deposition gas according to item 1.

[0017] Section 12. Item 1. Use of the deposition gas according to item 1 for semiconductor manufacturing, in which deposition is carried out on a substrate for semiconductor manufacturing. [Effects of the Invention]

[0018] According to the present disclosure, a deposition gas containing hydrofluoroethylene can be newly provided. [Brief explanation of the drawings]

[0019] [Figure 1] Figure 1 is a diagram for explaining the evaluation of the etching resistance of a deposition film. A slow etching rate of a deposition film indicates high etching resistance, which indicates that etching resistance is desirable. ■: 1,1-difluoroethylene (CH2=CF2) ◆: c-C4F8 [Figure 2] Figure 2 is a diagram illustrating the evaluation of the adhesion of the deposition film. (A) Plasma treatment was performed with each gas on a 2 μm line and a 2 μm space (3.5 μm resist / Si substrate), and the film thickness was measured on the mask surface, sidewall, and Si surface. (B) A graph showing the film thickness on the Si surface relative to the sidewall. Horizontal axis: Sidewall film thickness [nm] Vertical axis: Si surface film thickness [nm] Straight line with intercept 0 ●: C3F6 ×: 1,2-difluoroethylene ▲: 1,1-difluoroethylene ■: c-C4F8 [Figure 3]Figure 3 shows the experimental equipment used for TSV processing. The experimental equipment parameters (variables) of ICP power, process pressure, bias power, and gas flow rate were selected, and under these conditions, a protective film was deposited on the Poly-Si film using the experimental equipment, and data (deposition rate (DR)) was collected. [Figure 4] Figure 4 shows the distribution of deposition rates (DR) calculated using a digital twin constructed using a predictive model. The vertical axis represents the deposition rate value, and the horizontal axis represents the gas species. When the virtual experiment results were verified using an actual experimental device, it was revealed that the alternative gas candidates CHF=CHF and CH2=CF2 had higher deposition rates than c-C4F8 and C3F6. The maximum deposition rates (DR) were in the order CH2=CF2 > CHF=CFH > C3F6 ≒ c-C4F8. CH2=CF2 and CHF=CFH were superior to c-C4F8 in terms of the maximum DR. [Figure 5] Figure 5 shows that the equipment parameters that affect the deposition rate (DR) differ depending on the gas type. Among the equipment parameters, the parameters that affect the deposition rate (DR) are the ICP power and gas flow rate for FC-based gases, and the gas flow rate for HFC-based gases. [Figure 6]Figure 6 shows the deposition film production experiment. Radicals (neutral particles) in CH2=CF2 plasma were measured using a quadrupole mass spectrometer (QMS) EQP manufactured by Hiden Analytical, attached to the side wall of the experimental apparatus. The QMS measurement was performed in RGA mode, and a positive voltage was applied to prevent positive ions from entering the QMS, allowing only neutral particles to be taken in through a 100 μm diameter orifice. Electrons accelerated at 70 eV were collided with the taken-in neutral particles, and the amount of ionized particles was measured for each mass number (m / z). m represents the mass number of the neutral particle being measured, and z represents the valence of the ionized particle. The experimental equipment parameters (variables) were selected: ICP power (900W-2700W), process pressure (10mTorr-60mTorr), bias power (0W), gas flow rate (60sccm-175sccm), and electrostatic chuck (ESC, -10℃). Under these conditions, a deposition film was deposited on a Poly-Si film using the experimental equipment, and the deposition rate (DR) was collected. Radicals were measured using QMS in the mass range of 1≦m / z≦150 (2.5 times the molecular weight of the deposition gas). The measured intensity for each mass number (m / z) was multiplied by √m, and the mass-dependence of the QMS measurement sensitivity was corrected. [Figure 7] Figure 7 shows the correlation between the horizontal axis (relative intensity of CH2=CF2 (m / z=64)) * (square of source power density) and the vertical axis (deposition rate (DR)). The relative intensity is the relative intensity obtained by dividing the radical intensity of the desired m / z by the sum of the radical intensities for mass numbers 1≦m / z≦150. The radical intensity is the measured intensity of each mass number (m / z) * (√m), and the value obtained by multiplying the measured intensity of each mass number (m / z) by √m to correct for the mass dependence of the QMS measurement sensitivity. The horizontal axis is the relative intensity of CH2=CF2 (m / z=64)) * (square of source power density). The vertical axis is the deposition rate (DR) [nm / min]. The source power is the inductively coupled plasma (ICP) power used for deposition. DETAILED DESCRIPTION OF THE INVENTION

[0020] In this specification, "containing" is a concept that encompasses all of "comprise," "consist essentially of," and "consist only of." In this specification, when a numerical range is expressed as "A to B," it means "A or more and B or less." When parts, % and the like are used in this specification, these represent parts by mass, parts by weight, mass %, or weight % (wt%).

[0021] 1. Deposition gas In the miniaturization and high integration technology of semiconductor devices, three-dimensional integration technology, such as chiplets, which realizes integration, is attracting attention and is being introduced. ) is a new design methodology that divides a large integrated circuit (IC) into multiple small modules, or chiplets, and then highly integrates and packages them to improve performance. Three-dimensional integration technology is a technology that stacks transistors and other components vertically to increase the integration density of semiconductor devices.

[0022] A typical three-dimensional integration technology is the through-silicon via technology (TSV, TSV processing), which processes integration in the vertical direction of a silicon substrate, and is used in semiconductor device development. TSV is a technology that connects semiconductor chips by drilling thin holes (vias) that penetrate vertically through the silicon substrate and filling them with metal to create electrodes. To achieve TSV, etching (deep etching) with a width of several μm to several tens of μm and a depth of several tens to several hundred μm is required.

[0023] Deep etching is etching a substrate such as Si with a high aspect ratio.

[0024] Deep etching is mainly performed using a method known as the Bosch process. The Bosch process is a plasma processing method that sequentially repeats the following steps: an etching process in which a substrate is etched using plasma of an etching gas; a deposition ((sidewall) protective film formation) process in which a protective film is formed in the recess formed by the etching process using plasma of a protective film forming gas (deposition gas); and a process in which the surface to be etched is exposed by plasma processing.

[0025] The conventional Bosch process uses gases with high global warming potential (GWP), such as c-C4F8 (GWP: 10,300), CF4 (GWP: 7,390), SF6 (GWP: 24,300), CHF3 (GWP: 14,800), and CH2F2 (GWP: 675), for microfabrication, making it an environmentally hazardous process.

[0026] The conventional Bosch process requires frequent gas switching depending on the process, which reduces the productivity of semiconductor chips.The conventional Bosch process can also deteriorate the electrical characteristics of semiconductor chips due to the processing shape (scallops: sharp uneven shapes that occur as unetched parts on the etched surface) caused by the process.

[0027] Therefore, unlike the Bosch process, a plasma processing method (non-Bosch process) has been proposed in which etching and deposition are performed simultaneously.

[0028] Conventional non-Bosch processes also use c-C4F8 and SF6, gases with high GWP, and are therefore environmentally hazardous processes.

[0029] The present disclosure relates to a method for depositing a semiconductor on a substrate for semiconductor manufacturing during semiconductor manufacturing. This includes deposition gases containing hydrofluoroethylene, which are used for the purpose of

[0030] Deposition gases are used in chemical vapor deposition (CVD) processes in thin film and semiconductor manufacturing. It is a gas used to deposit thin films in processes such as CVD (Chemical Vapor Deposition) and PVD (Physical Vapor Deposition).

[0031] Hydrofluoroethylene The deposition gas of the present disclosure uses hydrofluoroethylene, a low GWP gas, and can perform deposition effectively on semiconductor manufacturing substrates in both Bosch and non-Bosch processes.

[0032] In the deposition gas of the present disclosure, the hydrofluoroethylene is preferably composed of difluoroethylene and 1,1,2-trifluoroethylene (HFO-1123). At least one hydrofluoroethylene selected from the group is used, and more preferably difluoroethylene is used.

[0033] Difluoroethylenes include 1,1-difluoroethylene (HFO-1132a), trans-1,2-difluoroethylene (HFO-1132(E), GWP: 0.0036), and cis-1,2-difluoroethylene (HFO-1132(Z)).

[0034] The deposition gas of the present disclosure may use one type of hydrofluoroethylene alone, or may use a mixture (blend) of two or more types of hydrofluoroethylene.

[0035] The deposition gas of the present disclosure contains fluoroethylene. From the viewpoint of deposition rate (DR), the deposition gas of the present disclosure preferably contains 1 to 99% by volume, and more preferably 10 to 90% by volume, of fluoroethylene, where the total volume of the deposition gas is 100% by volume.

[0036] Other deposition gases The deposition gas of the present disclosure may contain other deposition gases from the viewpoint of deposition rate (DR) and adhesion in the manufacture of semiconductor devices, and may contain, for example, hydrofluorocarbon compounds (HFCs) such as CH2F2, C2H4F2, and C3H2F4; perfluorocarbon compounds (PFCs) such as CF4, C2F6, C3F8, C4F8, C3F6, C4F6, and C5F8; iodides such as CF3I, C2F5I, and C3F7I; and the like.

[0037] The deposition gas of the present disclosure may be one of these other deposition gases, or a mixture (blend) of two or more of them.

[0038] inert gas The deposition gas of the present disclosure may contain an inert gas as needed from the viewpoint of deposition rate (DR). Examples of the inert gas include one or more of rare gases, nitrogen, etc. Examples of rare gases include helium, neon, argon, xenon, krypton, etc., with argon being preferred. These inert gases may be used alone or in combination (blended) of two or more.

[0039] Deposition Gas The deposition gas of the present disclosure exhibits a high deposition rate (DR) on semiconductor manufacturing substrates.

[0040] The deposition gas disclosed herein employs the Bosch process in plasma processing, and as a result, has a high deposition rate (DR), high film resistance, functions with thin films, and is easy to remove, for substrates such as Si used in semiconductor manufacturing, leading to improved productivity of substrates used in semiconductor manufacturing.

[0041] When using the Bosch process to deposit semiconductor manufacturing substrates, a protective film is deposited on top of the material to be etched. If the protective film has too high an etching resistance, it cannot be removed by plasma processing, and etching does not proceed.

[0042] The deposition gas of the present disclosure forms a deposited film exhibiting high film resistance by deposition (plasma processing). However, as described in the examples of this specification, the protective film formed using the deposition gas of the present disclosure can be removed using the etching gas SF6 under bias conditions, and functions well as a deposition gas for the Bosch process.

[0043] The deposition gas of the present disclosure is preferably a deposition gas used in a plasma process for manufacturing a substrate having a through-silicon via (TSV), including a Bosch process and a non-Bosch process.

[0044] The deposition gas of the present disclosure is more preferably a deposition gas for deposition in the Bosch process in the manufacture of substrates with through silicon vias (TSVs).

[0045] In the manufacture of substrates with through-silicon vias (TSVs), the Bosch process is adopted, and by using the deposition gas disclosed herein in the deposition process, it is possible to etch the substrate with a high aspect ratio (deep etching).

[0046] The deposition gas of the present disclosure is a low GWP gas, enabling environmentally friendly and sustainable microfabrication technology for semiconductor manufacturing substrates using the Bosch process.

[0047] 2. How to do the deposition The present disclosure includes a method of performing deposition on a semiconductor manufacturing substrate using a deposition gas containing the hydrofluoroethylene (preferably difluoroethylene) of the present disclosure as the gas supplied to generate plasma.

[0048] The deposition method of the present disclosure is preferably a method of performing deposition on a substrate for semiconductor manufacturing, which substrate has through-silicon vias (TSVs), using the deposition gas of the present disclosure in a plasma process. The plasma process of the present disclosure includes a Bosch process and a non-Bosch process.

[0049] The deposition method of the present disclosure is more preferably a method of performing deposition on a substrate having a through-silicon via (TSV) as a substrate for semiconductor manufacturing, employing the Bosch process in plasma processing and using the deposition gas of the present disclosure.

[0050] In the manufacture of substrates with through-silicon vias (TSVs), the plasma processing preferably employs the Bosch process, and by using the deposition gas of the present disclosure in the deposition process, it is possible to etch the substrate with a good high aspect ratio (deep etching).

[0051] The present disclosure relates to a gas supplied to a semiconductor manufacturing substrate to generate plasma. The present disclosure also encompasses a method of adjusting the deposition rate (DR) and performing deposition using a deposition gas containing hydrofluoroethylene (preferably difluoroethylene).

[0052] Using a quadrupole mass spectrometer (QMS), the deposition gas (CH2=CF2, etc.) The radicals in the plasma generated by the irradiation are measured. QMS measurement conditions at this time: Measurement mode: RGA mode (blocks positive ions) Orifice size: 100 μmφ Electron energy to ionize a neutral particle: 70 eV Measurement mass range: 1≦m / z≦150

[0053] Experimental equipment parameters (variables) Inductively Coupled Plasma (ICP) Power: 900W~2700W Process pressure: 10mTorr to 60mTorr Bias power: 0W Gas flow rate: 60sccm to 175sccm Electrostatic chuck (ESC): -10℃

[0054] The experimental equipment parameters are selected, and under those conditions, a deposition film is deposited on a Poly-Si film using the experimental equipment, and the deposition rate (DR) is collected.

[0055] The radical intensity is measured for mass numbers in the range of 2.5 times the molecular weight of the deposition gas (CH2=CF2, etc.) (for CH2=CF2, 1≦m / z≦150), and each intensity is multiplied by √m (m: mass number of each neutral particle). By multiplying each intensity by √m, the mass dependency of the measurement sensitivity of the QMS is corrected.

[0056] The relative intensity is calculated by dividing the radical intensity of a desired m / z by the sum of the radical intensities of mass numbers in the range 1≦m / z≦150.

[0057] The radical intensity is calculated by multiplying the measured intensity of each mass number (m / z) by √m to correct for the mass dependency of the QMS measurement sensitivity.

[0058] The radical strength of the deposition gas can be adjusted as appropriate by adjusting the radical generation conditions, such as the temperature of the semiconductor manufacturing substrate during deposition and the experimental equipment parameters (ICP power, process pressure, bias power, gas flow rate, ESC, etc.).

[0059] In the deposition method of the present disclosure, deposition is performed on a semiconductor manufacturing substrate using the deposition gas of the present disclosure, adjusting the deposition rate (DR) under conditions that satisfy the following formula:

[0060] (1) Source power area density: W / cm 2 At the time Deposition rate (DR)=-6.8*10 14 *x 2 +1.5*10 9 *x (2) Volume density of source power: W / cm 3 At the time Deposition rate (DR)=-6.6*10 19 *x 2 +4.7*10 11 *x

[0061] x = (relative intensity of deposition gas) * (square of source power density)

[0062] Relative intensity: The radical intensity of the desired m / z of the deposition gas measured using a quadrupole mass spectrometer (QMS) is 1≦m / z≦150 (2.5 times the molecular weight of the deposition gas). is the relative intensity divided by the sum of the radical intensities of the mass numbers.

[0063] Radical intensity: (measured intensity of each mass number (m / z)) * (√m) The radical intensity is calculated by multiplying the measured intensity of each mass number (m / z) by √m, and this corrects for the mass dependency of the measurement sensitivity of the QMS.

[0064] m: molecular weight z: Charge ionized in QMS

[0065] Source Power Density: Source power: Inductively coupled plasma (ICP) power during deposition (unit: W) (1) Source power area density (unit: W / cm 2 ) (2) Source power volume density (unit: W / cm 3 )

[0066] Relative intensity of CH2=CF2 (m / z=64)*(square of source power density) (1) Area of ​​the dielectric window where plasma is generated: 2,640 cm 2 (2) Volume of the plasma generation region: 46,600 cm 3

[0067] In the deposition method, the deposition rate (DR) is preferably 500 nm / min or higher.

[0068] In the formula x = (relative intensity of deposition gas) * (square of source power density), the range of x is determined by the source power density (1) source power area density (unit: W / cm 2 ), preferably 4.0*10 -7 ~ 2.0*10 -6 is. 4.0*10 -7 ≦ x ≦ 2.0*10 -6

[0069] In the formula x = (relative intensity of deposition gas) * (square of source power density), the range of x is determined by dividing the source power density by (2) the source power volume density (unit: W / cm 3 ), preferably 1.3*10 -9 ~ 6.0*10 -9 is. 1.3*10 -9 ≦ x ≦ 6.0*10 -9

[0070] The ICP power is preferably adjusted in the range of 900W to 2700W.

[0071] 3.Semiconductor manufacturing equipment . The present disclosure encompasses a semiconductor manufacturing apparatus having a gas jetting portion for a deposition gas containing the hydrofluoroethylene of the present disclosure.

[0072] 4. Semiconductor manufacturing method The present disclosure includes a method for manufacturing a semiconductor, in which deposition is performed on a semiconductor manufacturing substrate using a deposition gas containing the hydrofluoroethylene of the present disclosure.

[0073] 5. Use in semiconductor manufacturing The present disclosure includes the use of a deposition gas containing the hydrofluoroethylene of the present disclosure for semiconductor manufacturing to perform deposition on a semiconductor manufacturing substrate.

[0074] The deposition gas of the present disclosure can be applied to a Bosch process, in which the following processes are repeated in order: an etching process in which a substrate is etched using plasma of an etching gas; a deposition process in which a protective film is formed in a recess formed by the etching process using plasma of the deposition gas of the present disclosure; and a process in which the surface to be etched is exposed by plasma treatment. This is a preferred deposition method for substrates such as Si substrates used in semiconductor manufacturing. This indicates the position rate (DR) and leads to improved productivity of substrates used in semiconductor manufacturing.

[0075] While the embodiments of the present disclosure have been described above, various changes in form and details are possible without departing from the spirit and scope of the claims. [Example]

[0076] The present disclosure will be specifically described below using examples and comparative examples, but the present disclosure is not limited to these examples alone.

[0077] Plasma processing methods of examples and comparative examples (1) Deposit Rate (DR) The source power dependence of deposition rate (DR), which is one of the important characteristics of deposition gas, was evaluated.

[0078] Deposition (preparation of deposited film) Deposition was performed on a silicon substrate (Si) and a silicon oxide film (SiO2, TEOS) formed on the silicon substrate using an ICP (Inductively Coupled Plasma) device under the following deposition conditions: gas flow rate 20 sccm, pressure 10 mTorr, bias 0 W, and source power 100 W, 200 W, and 300 W (Table 1). Deposition gas: 1,2-difluoroethylene (CHF=CHF) Deposition gas: octafluorocyclobutane (c-C4F8)

[0079] [Table 1]

[0080] In the example (CHF = CHF), deposition was confirmed, and the DR was larger than in the comparative example (c-C4F8). The deposition gas of the present disclosure contains hydrofluoroethylene, and is expected to shorten the deposition process time in plasma processing methods, making it useful as a deposition gas.

[0081] (2) Sputtering resistance Using Ar-sputtering with XPS (X-ray Photoelectron Spectroscopy), the sputtering rate of the deposited film was calculated and the hardness (sputtering resistance) of the film was evaluated in a structure consisting of a deposited film (deposition gas: CHF = CHF, or c-C4F8) / polysilicon film (PolySi) / silicon oxide film (SiO2) / silicon substrate (Si).

[0082] Deposition (preparation of deposited film) Deposition was performed on a silicon substrate (Si) and a silicon oxide film (SiO2) formed on the silicon substrate under the deposition conditions of an ICP device, a gas flow rate of 70 sccm, a pressure of 5 mTorr, a bias of 0 W, and a source power of 200 W.

[0083] sputtering In the example (deposition gas: CHF = CHF), the deposited film was hardly scraped off even after a long sputtering time. In the comparative example (deposition gas: c-C4F8), the deposited film was scraped off.

[0084] In the example (CHF = CHF), a harder deposited film was obtained in Ar-GCIB (Gas Cluster Ion Beam) sputtering (5 kV, 20 nA) compared to the comparative example (c-C4F8). The deposition gas of the present disclosure contains hydrofluoroethylene, and in the plasma processing method, a deposited film with sputtering resistance can be prepared.

[0085] (3) Etching resistance Deposition film production Deposited films were formed by varying the equipment parameters (ICP power, system pressure, bias power, and gas flow rate) at the levels shown in Table 2. The pattern was a 0.5 μm TEOS mask / Si substrate contact hole (hole diameter 2 μm), and the resistance of the deposited film deposited on the top (top of TEOS) was evaluated.

[0086] [Table 2]

[0087] Etching resistance of deposited films The deposited film was subjected to SF6 etching treatment using an ICP device (Processing time: 35 s (C2H2F2), 60 s (c-C4F8), ESC temp.: 20°C), and the etching rate of the deposited film was calculated from the difference between the film thickness at the time of deposition and the film thickness after etching treatment (Table 3).

[0088] [Table 3]

[0089] 1 is a diagram for explaining the evaluation of the etching resistance of a deposition film (deposited film). A slow etching rate of a deposited film indicates high etching resistance, which indicates desirable etching resistance. ■: 1,1-difluoroethylene (CH2=CF2) ◆:c-C4F8

[0090] In the example (CH2=CF2) (■), the etching rate (ER) was lower, loss of the deposited film was suppressed, and good etching resistance was achieved compared to the comparative example (c-C4F8) (◆) (Table 3 and Figure 1). The deposition gas of the present disclosure contains hydrofluoroethylene, and in a plasma processing method, a deposited film with good etching resistance can be prepared.

[0091] (4) Evaluation of followability The adhesion of the deposition film was evaluated. In the evaluation of adhesion, it was found that in the Si deep trench processing (Bosch process), the deposition film adheres to the sidewall but does not adhere to the bottom surface. iIt is advantageous for deep drilling.

[0092] FIG. 2 is a diagram for explaining the evaluation of the throwing power of the deposition film.

[0093] (A) Conditions: Plasma treatment was performed with each gas on a 2 μm line and 2 μm space (3.5 μm resist / Si substrate), and the film thickness was measured on the mask surface, sidewall, and Si surface.

[0094] (B) Calculating the trendline 1 is a graph showing the film thickness of the Si surface relative to the sidewall. Horizontal axis: Sidewall thickness [nm] Vertical axis: Si surface thickness [nm] A straight line with an intercept of 0 ●:C3F6 ×: 1,2-difluoroethylene ▲: 1,1-difluoroethylene ■:c-C4F8

[0095] An approximate curve (linear equation) was calculated from the plots of each gas, and it was found that the deposition films formed using 1,2-difluoroethylene (×) or 1,1-difluoroethylene (▲) had a smaller slope than the deposition films formed using c-C4F8 (■) or C3F6 (●).

[0096] Gases that are difficult to deposit on the Si surface (bottom) compared to the sidewall According to the approximation curve (Figure 2), when c-C4F8 (■) is used to create a 100 nm thick film on the sidewall (horizontal axis), a film with a thickness of approximately 190 nm (vertical axis) is formed on the bottom surface (Si surface). On the other hand, when CH2=CF2 (▲) is used to create a 100 nm thick film on the sidewall (horizontal axis), a film with a thickness of approximately 110 nm (vertical axis) is formed on the bottom surface (Si surface). CH2=CF2 (▲) can form a deposition film that does not easily adhere to the bottom surface (Si surface) (it adheres thinly to the bottom surface (Si surface)).

[0097] Hydrofluoroethylenes such as 1,2-difluoroethylene and 1,1-difluoroethylene are gases that are difficult to deposit on the Si surface (bottom) compared to the sidewalls (Figure 2, Table 4). In deep Si etching (Bosch process), which etches Si while protecting the sidewalls, hydrofluoroethylenes can be evaluated as forming an advantageous deposition film.

[0098] [Table 4]

[0099] Generally, in Si deep trench processing (Bosch process), it is desirable that the deposition film is thinly attached to the bottom surface of the recess formed by etching. The present disclosure provides a method for forming a deposition film using a deposition gas containing hydrofluoroethylene such as 1,2-difluoroethylene or 1,1-difluoroethylene, and using c-C4F8 or C3F Compared to the deposition film formed using 6, the deposition film adheres thinly to the bottom surface of the recess formed by etching, and can be evaluated as being superior, especially in Si deep trench processing (Bosch process).

[0100] (5) Development of low-GWP gas for high-efficiency TSV using digital twin Figure 3 shows the experimental equipment used for TSV processing. The experimental equipment parameters (variables) were selected, and data (deposition rate (DR)) was collected by depositing a protective film on the Poly-Si film.

[0101] A search for low-GWP gases for high-efficiency TSVs was conducted using digital twins. Digital twins refer to virtual (but alternate reality with the same effects as reality) objects, systems, or processes that are reproduced on a computer.

[0102] A distinctive feature of the gas exploration process using digital twins is that comprehensive virtual experiments are conducted on the digital twin using a "predictive model" built on the basis of streamlined experiments.

[0103] First, from a chemical standpoint, we searched for alternative gas candidates that have a performance superior to that of the existing c-C4F8 in terms of deposition rate, which is the performance index of deposition gas. C3F6, CHF=CHF, and CH2=CF2 were selected as alternative gas candidates.

[0104] Next, we used experimental design to obtain optimal parameter settings with a small number of experiments. Experimental design is an applied field of mathematical statistics, and is a method for researching highly efficient experimental planning and analysis methods by investigating the effect of specific factors on a target. Based on this, we selected 19 conditions for the actual experimental equipment parameters (variables) of ICP power, process pressure, bias power, and gas flow rate, and conducted actual experiments based on these conditions.

[0105] The experiment used the same type of experimental equipment (Figure 3) used for TSV processing in mass production, and involved depositing a protective film on a Poly-Si film and collecting data (deposition rate (DR)).

[0106] Next, a "prediction model" was constructed from the experimental results to predict deposition rate (DR) based on equipment parameters. Using this prediction model, a digital twin was constructed that reproduced actual process conditions, and 490 virtual experiments were comprehensively performed in the digital space to calculate the distribution of deposition rate (DR).

[0107] Figure 4 shows the distribution of deposition rate (DR) calculated by constructing a digital twin using a predictive model.

[0108] In Figure 4, the vertical axis represents the deposition rate and the horizontal axis represents the gas species. When the results of this virtual experiment were verified using actual experimental equipment, it became clear that the alternative gas candidates for CHF=CHF and CH2=CF2 had higher deposition rates than c-C4F8 and C3F6 (Figure 4).

[0109] Generally, the search for alternative gases basically takes a local optimum solution approach, searching around the conditions used for the reference gas (c-C4F8, currently used as the deposition gas).By using a digital twin, it is possible to search for gases in a wide condition space, which makes it possible to find the global optimum solution and also shorten the experimental time from 245 hours to around 30 minutes.

[0110] The maximum deposition rate (DR) is CH2=CF2>CHF=CFH>C3F6≒c-C4 The highest DR values ​​were observed for CH2=CF2 and CHF=CFH, compared to c-C4F8 and C3F6 (Figure 4).

[0111] FIG. 5 shows that the equipment parameters that affect the deposition rate (DR) differ depending on the gas species.

[0112] It was revealed that the equipment parameters that affect the deposition rate (DR) differ depending on the gas type (Figure 5). For c-C4F8 and C3F6 FC gases, it was found that among the equipment parameters, ICP power and gas flow rate affect the deposition rate (DR). For CHF=CHF and CH2=CF2 HFC gases, it was found that among the equipment parameters, gas flow rate affects the deposition rate (DR). By using digital twin technology, it was possible to search for low-GWP gases (environmental load reduction effects) for high-efficiency TSV.

[0113] (6) Development of deposition method to adjust deposition rate (DR) FIG. 6 shows an experiment on the formation of a deposition film.

[0114] Using a quadrupole mass spectrometer (QMS), radicals of deposition gas (CH2=CF2) in the plasma were measured, and the ion density was measured.

[0115] QMS measurement conditions at this time: Measurement mode: RGA mode (blocks positive ions) Orifice size: 100 μmφ Electron energy to ionize a neutral particle: 70 eV Measurement mass range: 1≦m / z≦150

[0116] Experimental parameters (variables) were selected, and under those conditions, deposition films were deposited on Poly-Si films using the experimental equipment, and deposition rates (DR) were collected.

[0117] Experimental equipment parameters (variables) ICP power: 900W~2700W Process pressure: 10mTorr to 60mTorr Bias power: 0W Gas flow rate: 60sccm to 175sccm Electrostatic chuck (ESC): -10℃

[0118] The radical intensity of the mass number in the range of 2.5 times the molecular weight of the deposition gas (CH2=CF2, etc.) (for CH2=CF2, 1≦m / z≦150) is measured, and each intensity is multiplied by √m (m: molecular weight). By multiplying each intensity by √m, the mass dependency of the measurement sensitivity of the QMS is corrected.

[0119] The relative intensity was calculated by dividing the radical intensity of the desired m / z in the deposition gas by the sum of the radical intensities of mass numbers in the range 1≦m / z≦150.

[0120] The radical intensity was calculated as (measured intensity of each mass number (m / z)) * (√m), and the measured intensity of each mass number (m / z) was multiplied by √m to correct for the mass dependence of the QMS measurement sensitivity.

[0121] The radical strength of the deposition gas was adjusted appropriately based on radical generation conditions such as the temperature of the semiconductor manufacturing substrate during deposition and experimental equipment parameters (ICP power, process pressure, bias power, gas flow rate, ESC, etc.).

[0122] As shown in Figure 6, radicals (neutral particles) in the CH2=CF2 plasma were measured using a quadrupole mass spectrometer (QMS) EQP manufactured by Hiden Analytical, which was attached to the side wall of the experimental apparatus. The QMS measurement at this time was performed in RGA mode, and positive voltage was applied to prevent positive ions from flowing into the QMS, and only neutral particles were taken in through a 100 μm diameter orifice.

[0123] The captured neutral particles were bombarded with electrons accelerated at 70 eV to measure the amount of ionized particles for each mass number (m / z). m represents the molecular weight of the neutral particle being measured. z represents the charge of the particle ionized within the QMS.

[0124] Using QMS, radical measurements were performed in the mass number range of 1≦m / z≦150 (2.5 times the molecular weight of the deposition gas), and the measurement intensity for each mass number (m / z) obtained was multiplied by √m, thereby correcting the mass number dependence of the measurement sensitivity of the QMS.

[0125] FIG. 7 is a diagram showing the correlation between the horizontal axis (relative intensity of CH2=CF2 (m / z=64))*(square of source power density) and the vertical axis (deposition rate (DR)).

[0126] The relative intensity is calculated by dividing the radical intensity of a desired m / z by the sum of the radical intensities of mass numbers in the range of 1≦m / z≦150.

[0127] The radical intensity is the measured intensity of each mass number (m / z) * (√m) and the value obtained by multiplying the measured intensity of each mass number (m / z) by √m to correct for the mass dependency of the QMS measurement sensitivity.

[0128] Horizontal axis: (relative intensity of CH2=CF2 (m / z=64)) * (square of source power density) Vertical axis: Deposition rate (DR) [nm / min] Source Power: The inductively coupled plasma (ICP) power at which the deposition takes place.

[0129] [Table 5]

[0130] [Table 6]

[0131] From the experimental results, in the method of depositing onto a substrate for semiconductor manufacturing, the deposition rate (DR) can be adjusted using a deposition gas under the condition that satisfies the following formula.

[0132] (1) Source power area density: W / cm 2 At the time Deposition rate (DR)=-6.8*10 14 *x 2 +1.5*10 9 *x (2) Volume density of source power: W / cm 3 At the time Deposition rate (DR)=-6.6*10 19 *x 2 +4.7*10 11 *x

[0133] x = (relative intensity of deposition gas) * (square of source power density)

[0134] Relative intensity: The relative intensity is calculated by dividing the radical intensity of the desired m / z measured using a quadrupole mass spectrometer (QMS) by the sum of the radical intensities of mass numbers in the range of 1≦m / z≦150 (2.5 times the molecular weight of the deposition gas).

[0135] Radical intensity: (measured intensity of each mass number (m / z)) * (√m) The radical intensity is calculated by multiplying the measured intensity of each mass number (m / z) by √m, and this corrects for the mass dependency of the measurement sensitivity of the QMS.

[0136] m: molecular weight z: Charge ionized in QMS

[0137] Source Power Density: Source power: Inductively coupled plasma (ICP) power during deposition (unit: W) (1) Source power area density (unit: W / cm 2 ) (2) Source power volume density (unit: W / cm 3 )

[0138] Relative intensity of CH2=CF2 (m / z=64)*(square of source power density) (1) Area of ​​the dielectric window where plasma is generated: 2,640 cm 2 (2) Volume of the plasma generation region: 46,600 cm 3

[0139] In the deposition method, the deposition rate (DR) is preferably 500 nm / min or higher.

[0140] From the experimental results, the range of x in the formula x = (relative intensity of deposition gas) * (square of source power density) is as follows: (1) source power area density (unit: W / cm 2 ), it is 4.0*10 -7 ~ 2.0*10 -6 It was. 4.0*10 -7 ≦ x ≦ 2.0*10-6

[0141] From the experimental results, the range of x in the formula x = (relative intensity of deposition gas) * (square of source power density) is as follows: (1) source power density (unit: W / cm 3 ), it is 1.3*10 -9 ~ 6.0*10 -9 It was. 1.3*10 -9 ≦ x ≦ 6.0*10 -9

[0142] This disclosure can provide a new, environmentally friendly deposition gas for TSV processing (a low-GWP gas for highly efficient TSV), which will contribute greatly to reducing the environmental impact as 3D integration technology becomes more widespread and its adoption progresses. This disclosure can provide a gas for miniaturization and high stacking, as well as a gas that emphasizes environmental performance for reducing the environmental impact and using energy with high efficiency.

Claims

1. Deposition gas containing hydrofluoroethylene.

2. The deposition gas of claim 1 , wherein the hydrofluoroethylene is difluoroethylene.

3. 10. The deposition gas of claim 1 for deposition in a plasma process in the manufacture of substrates with through silicon vias (TSV).

4. 10. The deposition gas of claim 1 for deposition in a Bosch process in the manufacture of substrates with through silicon vias (TSV).

5. A method of depositing a semiconductor on a substrate for manufacturing the semiconductor, using the deposition gas of claim 1.

6. the substrate is a substrate including a through silicon via (TSV), 6. The method of claim 5, wherein the deposition gas of claim 1 is used for plasma processing deposition.

7. the substrate is a substrate including a through silicon via (TSV), In the Bosch process, Deposition is performed using the deposition gas according to claim 1. The method of claim 5.

8. A method of depositing a semiconductor on a substrate for manufacturing, comprising: Using the deposition gas described in Item 1, The method includes adjusting the deposition rate (DR) so as to satisfy the following formula: (1) Area density of source power: W / cm ２ At the time Accumulation rate (DR) = -6.8 * 10 １４ *x ２ +1.5*10 ９ *x (2) Volume density of source power: W / cm ３ At the time Accumulation rate (DR) = -6.6 * 10 １９ *x ２ +4.7*10 １１ *x x = (relative intensity of deposition gas) * (square of source power density) Relative intensity: The relative intensity is calculated by dividing the radical intensity of a desired m / z measured using a quadrupole mass spectrometer (QMS) by the sum of the radical intensities of mass numbers in the range of 1≦m / z≦150 (2.5 times the molecular weight of the deposition gas). Radical intensity: (measured intensity of each mass number (m / z)) * (√m) The radical intensity is calculated by multiplying the measured intensity of each mass number (m / z) by m, and thereby correcting the mass dependency of the measurement sensitivity of the QMS. m: molecular weight z: ionized charge in QMS Source Power Density: Source power: Inductively coupled plasma (ICP) power during deposition (unit: W) (1) Source power area density (unit: W / cm ２ ) (2) Source power volume density (unit: W / cm ３ ) CH ２ =CF ２ (m / z=64) relative intensity * (square of source power density) (1) Area of ​​the dielectric window for plasma generation: 2,640 cm ２ (2) Volume of the plasma generation region: 46,600 cm ３

9. In the above formula, x=(relative intensity of deposition gas)*(square of source power density), The range of x is The source power density is defined as (1) the source power area density (unit: W / cm ２ ) is expressed as 4.0*10 －７ ≦ x ≦ 2.0 * 10 －６ or The source power density is defined as (2) the source power volume density (unit: W / cm ３ ) is expressed as 1.3*10 －９ ≦ x ≦ 6.0 * 10 －９ The method of claim 8, wherein

10. A semiconductor manufacturing device comprising the gas ejection portion for the deposition gas according to claim 1.

11. A method for manufacturing a semiconductor, comprising depositing a gas onto a substrate for manufacturing a semiconductor using the deposition gas according to claim 1.

12. 10. Use of the deposition gas according to claim 1 for semiconductor manufacturing, in which deposition is carried out on a semiconductor manufacturing substrate.

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