Deposition gas

Abstract

The purpose of the present disclosure is to newly provide a deposition gas. Provided is a deposition gas.

Description

Deposition Gas

[0001] The present disclosure relates to deposition gases.

[0002] Patent Document 1 discloses ４ F ８ and 2,3,3,3-tetrafluoropropene as a mixed gas for plasma treatment.

[0003] International Publication No. WO2022 / 074708A1

[0004] The present disclosure aims to provide a novel deposition gas containing hydrofluoroethylene.

[0005] The present disclosure encompasses the following configurations.

[0006] Item 1. A deposition gas containing hydrofluoroethylene.

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

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

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

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

[0011] Item 6. The method according to Item 5, wherein the substrate is a substrate having a through-silicon via (TSV), and the deposition gas according to Item 1 is used to perform plasma deposition.

[0012] Item 7. The method according to Item 5, wherein the substrate is a substrate including a through-silicon via (TSV), and deposition is performed using the deposition gas according to Item 1 in a Bosch process.

[0013] Item 8. A method for performing deposition on a semiconductor manufacturing substrate, using the deposition gas according to Item 1, and adjusting the deposition rate (DR) under the condition that satisfies the following formula: (1) areal density of source power: W / cm ２ When the deposition rate (DR) is -6.8*10 １４ *x ２ +1.5*10 ９ *x (2) Volume density of source power: W / cm ３ When the deposition rate (DR) is -6.6*10 １９ *x ２ +4.7*10 １１ *x x = (relative intensity of deposition gas) * (square of source power density) Relative intensity: This is the relative intensity obtained 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 the mass numbers 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 is used to correct the mass dependency of the measurement sensitivity of the QMS. m: molecular weight z: ionized charge in the QMS Source power density: Source power: inductively coupled plasma (ICP) power when performing deposition (unit: W) (1) Source power areal 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 ​​dielectric window for plasma generation: 2,640 cm ２ (2) Volume of the plasma generation region: 46,600 cm ３

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

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

[0016] Item 11. A method for manufacturing a semiconductor, comprising using the deposition gas according to Item 1 to perform deposition on a substrate for manufacturing a semiconductor.

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

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

[0019] FIG. 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 that etching resistance is desirable. ２ =CF ２ ) ◆: c-C ４ F ８ 2 is a diagram illustrating the evaluation of the deposition ability 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: film thickness on the sidewall [nm] Vertical axis: film thickness on the Si surface [nm] Straight line with intercept 0 ●: C ３ F ６ ×: 1,2-difluoroethylene ▲: 1,1-difluoroethylene ■: c-C ４ F ８Figure 3 is a diagram showing the experimental equipment used when performing 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 to collect data (deposition rate (DR)). Figure 4 is a diagram showing the distribution of deposition rate (DR) calculated by constructing a digital twin using a prediction model. The vertical axis represents the deposition rate value, and the horizontal axis represents the gas type. When the results of the virtual experiment were verified using the actual experimental equipment, it was found that CHF = CHF and CH ２ =CF ２ The alternative gas candidate is c-C ４ F ８ , and C ３ F ６ It was revealed that the deposition rate was high for CH. ２ =CF ２ >CHF=CFH>C ３ F ６ ≒ c-C ４ F ８ The maximum value of DR was c-C ４ F ８ In contrast, CH ２ =CF ２ and CHF=CFH were dominant. Figure 5 is a diagram showing that the equipment parameters that affect the deposition rate (DR) differ depending on the gas species. Among the equipment parameters, the parameters that affect the deposition rate (DR) are ICP power and gas flow rate for FC-based gases, and gas flow rate for HFC-based gases. Figure 6 is a diagram showing an experiment on the production of a deposition film. Using a quadrupole mass spectrometer (QMS) EQP manufactured by Hiden Analytical Co. attached to the side wall of the experimental equipment, ２ =CF ２Radicals (neutral particles) in the plasma were measured. The QMS measurement was performed using the RGA mode. A positive voltage was applied to prevent positive ions from entering the QMS, and only neutral particles were captured through a 100 μm diameter orifice. The captured neutral particles were bombarded with electrons accelerated at 70 eV to ionize the 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. z represents the valence of the ionized particle. The experimental equipment parameters (variables) were selected: ICP power (900 W to 2700 W), process pressure (10 mTorr to 60 mTorr), bias power (0 W), gas flow rate (60 sccm to 175 sccm), and electrostatic chuck (ESC, -10°C). Under these conditions, a deposition film was deposited on a poly-Si film using the experimental equipment, and the deposition rate (DR) was collected. Radical measurements were performed using QMS in the range of mass number 1≦m / z≦150 (2.5 times the molecular weight of the deposition gas), and the measurement intensity of each mass number (m / z) obtained was multiplied by √m, thereby correcting the mass number dependency of the measurement sensitivity of QMS. ２ =CF ２ This is a diagram showing the correlation between (relative intensity of m / z=64) * (square of source power density) and 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 of mass numbers 1≦m / z≦150. The radical intensity is (measured intensity of each mass number (m / z)) * (√m), which is a 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. Horizontal axis: (CH ２ =CF ２ (relative intensity of m / z=64) * (square of source power density). Vertical axis: deposition rate (DR) [nm / min]. Source power: inductively coupled plasma (ICP) power when deposition is performed.

[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 of semiconductor devices, three-dimensional integration technology, typified by chiplets, which realizes integration, is attracting attention and is being introduced. Chiplets are a new design method that divides a large integrated circuit (IC) into multiple small modules, or chiplets, and highly integrates and packages them to improve performance. Three-dimensional integration technology stacks transistors and other elements vertically to increase the integration level of semiconductor devices.

[0022] A typical three-dimensional integration technology is through-silicon via (TSV, TSV processing), which processes integration vertically on a silicon substrate, and is widely used in semiconductor device development. TSV is a technology that creates thin holes (vias) that penetrate vertically through a silicon substrate, embedding metal to create electrodes and connecting semiconductor chips. To create a TSV, etching (deep etching) with a width of several to several tens of microns and a depth of several tens to several hundred microns 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, which 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 involves the use of c-C ４ F ８ (GWP: 10,300), CF ４ (GWP: 7,390), SF ６ (GWP: 24,300), CHF ３ (GWP: 14,800), CH ２ F ２ Gases with high global warming potential (GWP), such as ethane (GWP: 675), are used in this process, 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 cause deterioration in the electrical characteristics of semiconductor chips due to the processing shape (scallops: sharp uneven shapes that occur as unetched parts on the etched surface).

[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] Even in the conventional Non-Bosch process, c-C ４ F ８ , S.F. ６ The conventional Non-Bosch process also places a high burden on the environment because it uses gases with high GWP.

[0029] The present disclosure encompasses a deposition gas containing hydrofluoroethylene for use in depositing on semiconductor manufacturing substrates during semiconductor manufacturing.

[0030] Deposition gases are gases used to deposit thin films in processes such as chemical vapor deposition (CVD) and physical vapor deposition (PVD) in thin film and semiconductor manufacturing.

[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 the Bosch process and non-Bosch process.

[0032] In the deposition gas of the present disclosure, at least one hydrofluoroethylene selected from the group consisting of difluoroethylene and 1,1,2-trifluoroethylene (HFO-1123) is preferably used as the hydrofluoroethylene, and difluoroethylene is more preferably 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 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 contains fluoroethylene in an amount of preferably 1 to 99% by volume, and more preferably 10 to 90% by volume, where the total amount 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. For example, CH ２ F ２ , C ２ H ４ F ２ , C ３ H ２ F ４ Hydrofluorocarbon compounds (HFCs) such as CF ４ , C ２ F ６ , C ３ F ８ , C ４ F ８ , C ３ F ６ , C ４ F ６ , C ５ F ８ Perfluorocarbon compounds (PFCs) such as CF ３ I, C ２ F ５ I, C ３ F ７ It may contain iodides such as I.

[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 the 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 of the present disclosure, by adopting the Bosch process in plasma processing, has a high deposition rate (DR), high film resistance, functions with thin films on substrates such as Si used in semiconductor manufacturing, and the films are easy to remove, leading to improved productivity of substrates used in semiconductor manufacturing.

[0041] In the Bosch process, a protective film is deposited on the substrate 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 will be explained in the examples of this specification, the protective film formed using the deposition gas of the present disclosure has high film resistance compared to the etching gas SF ６ It can be removed using HCl under bias conditions and works well as a deposition gas in the Bosch process.

[0043] The deposition gas of the present disclosure is preferably a deposition gas used in plasma processing for manufacturing a substrate with 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 Bosch process deposition 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 employed, 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).

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

[0047] 2. Deposition Method The present disclosure encompasses a method of depositing a semiconductor onto a substrate for manufacturing the semiconductor, using a deposition gas containing the hydrofluoroethylene (preferably difluoroethylene) of the present disclosure as a 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 a through-silicon via (TSV), 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 semiconductor manufacturing substrate, 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 treatment 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 includes a method for performing deposition on a semiconductor manufacturing substrate by adjusting the deposition rate (DR) using a deposition gas containing the hydrofluoroethylene (preferably difluoroethylene) of the present disclosure as a gas supplied to generate plasma on the substrate.

[0052] A quadrupole mass spectrometer (QMS) was used to measure the deposition gas (CH ２ =CF ２ The radicals in the plasma generated by the above method are measured. The QMS measurement conditions at this time are: Measurement mode: RGA mode (prevents positive ions from flowing in) Orifice size: 100 μmφ Electron energy for ionizing neutral particles: 70 eV Measurement mass number range: 1≦m / z≦150

[0053] Experimental equipment parameters (variables): Inductively coupled plasma (ICP) power: 900 W to 2700 W; Process pressure: 10 mTorr to 60 mTorr; Bias power: 0 W; Gas flow rate: 60 sccm to 175 sccm; Electrostatic chuck (ESC): -10°C

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

[0055] Deposition gas (CH ２ =CF ２ etc.) in the range of 2.5 times the molecular weight (CH ２ =CF ２ If m / z is 1≦m / z≦150, the radical intensities are measured, 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 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.).

[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) Area density of source power: W / cm ２ When the deposition rate (DR) is -6.8*10 １４ *x ２ +1.5*10 ９*x (2) Volume density of source power: W / cm ３ When the deposition rate (DR) is -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 relative intensity obtained by dividing the radical intensity of the desired m / z of the deposition gas measured using a quadrupole mass spectrometer (QMS) by the sum of the radical intensities of mass numbers 1≦m / z≦150 (2.5 times the molecular weight of the deposition gas).

[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 is used to correct the mass dependency of the measurement sensitivity of the QMS.

[0064] m: molecular weight z: ionized charge 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] CH ２ =CF ２ (m / z=64) Relative intensity * (square of source power density) (1) Area of ​​dielectric window for plasma generation: 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 It 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 It 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 Apparatus The present disclosure encompasses semiconductor manufacturing apparatus having a gas ejection portion for a deposition gas containing the hydrofluoroethylene of the present disclosure.

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

[0073] 5. Use for Semiconductor Manufacturing The present disclosure includes the use of a deposition gas containing the hydrofluoroethylene of the present disclosure for semiconductor manufacturing, in which deposition is performed on a semiconductor manufacturing substrate.

[0074] The deposition gas of the present disclosure can be applied to a Bosch process, which preferably involves sequentially repeating 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 processing. The deposition gas of the present disclosure exhibits a favorable deposition rate (DR) for substrates such as Si used in semiconductor manufacturing, leading 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.

[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) Deposition Rate (DR) The source power dependency of the deposition rate (DR), which is one of the important characteristics of a deposition gas, was evaluated.

[0078] Deposition (preparation of deposited film) A silicon substrate (Si) and a silicon oxide film (SiO ) formed on the silicon substrate were deposited under the deposition conditions of an ICP (Inductively Coupled Plasma) device, a gas flow rate of 20 sccm, a pressure of 10 mTorr, a bias of 0 W, and a source power of 100 W, 200 W, and 300 W. ２ Deposition was performed using 1,2-difluoroethylene (CHF=CHF) and octafluorocyclobutane (c-C ４ F ８ )

[0079]

[0080] In the example (CHF=CHF), deposition was confirmed, and in the comparative example (c-C ４ F ８ The deposition gas of the present disclosure contains hydrofluoroethylene, and is useful as a deposition gas in plasma processing methods, as it is expected to reduce the deposition process time.

[0081] (2) Sputtering resistance: The deposited film (deposition gas: CHF = CHF, or cC) was measured by Ar-sputtering using XPS (X-ray Photoelectron Spectroscopy). ４ F ８ ) / polysilicon film (PolySi) / silicon oxide film (SiO ２In a structure consisting of a thin film (SiO 2 ) / a silicon substrate (Si), the sputtering rate of the deposited film was calculated and the hardness (sputtering resistance) of the film was evaluated.

[0082] Deposition (preparation of deposited film) A silicon substrate (Si) and a silicon oxide film (SiO ) formed on the silicon substrate were deposited under the deposition conditions of an ICP apparatus, a gas flow rate of 70 sccm, a pressure of 5 mTorr, a bias of 0 W, and a source power of 200 W. ２ ) and deposition was carried out.

[0083] In the example (deposition gas: CHF = CHF deposited film), the deposited film was hardly scraped off even after a long sputtering time. ４ F ８ In the case of the deposition film using the etchant, the deposition film was scraped off.

[0084] In the example (CHF = CHF), Ar-GCIB (Gas Cluster Ion Beam) sputtering (5 kV, 20 nA) was used, and in the comparative example (c-C ４ F ８ The deposition gas of the present disclosure contains hydrofluoroethylene, and in a plasma processing method, it is possible to prepare a deposition film that is resistant to sputtering.

[0085] (3) Etching Resistance Deposition of Deposited Film (Deposition Film) Deposited films were formed by varying the apparatus 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 upper part (upper part of the TEOS) was evaluated.

[0086]

[0087] Etching resistance of deposited film Using an ICP device, SF ６Etching treatment (Processing time: 35 s (C2H2F2), 60 s (c-C4F8), ESC temp.: 20°C) was performed, and the etching rate of the deposited film was calculated from the difference between the film thickness at the time of film formation and the film thickness after etching treatment (Table 3).

[0088]

[0089] FIG. 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 that etching resistance is desirable. ２ =CF ２ ) ◆: c-C ４ F ８

[0090] Example (CH ２ =CF ２ ) (■) is the comparative example (c-C ４ F ８ ) (◆), the etching rate (ER) was lower, loss of the deposited film was suppressed, and the deposited film had good etching resistance (Table 3 and FIG. 1). The deposition gas of the present disclosure contains hydrofluoroethylene, and in a plasma processing method, a deposited film having good etching resistance can be prepared.

[0091] (4) Evaluation of Thickness The thickness of the deposition film was evaluated. In the evaluation of thickness, in Si deep trench processing (Bosch process), the deposition film adheres to the sidewall but does not adhere to the bottom surface, which is an advantage for Si deep trench processing.

[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 thicknesses on the mask surface, sidewall, and Si surface were measured.

[0094] (B) Calculation of the approximation curve A graph showing the film thickness of the Si surface relative to the sidewall. Horizontal axis: film thickness of the sidewall [nm] Vertical axis: film thickness of the Si surface [nm] Straight line with intercept 0 ●: C３ F ６ ×: 1,2-difluoroethylene ▲: 1,1-difluoroethylene ■: c-C ４ F ８

[0095] An approximate curve (linear equation) was calculated from the plots of each gas. The deposition film formed using 1,2-difluoroethylene (×) or 1,1-difluoroethylene (▲) showed a c-C ４ F ８ (■), or C ３ F ６ It was found that the inclination was smaller than that of the deposition film formed using (●).

[0096] Gas that is difficult to deposit on the Si surface (bottom) compared to the sidewall. According to the approximate curve (Figure 2), c-C ４ F ８ In the case of (■), when a film thickness of 100 nm (horizontal axis) is formed on the sidewall, a film thickness of about 190 nm (vertical axis) is formed on the bottom surface (Si surface). ２ =CF ２ In the case of (▲), it can be seen that when a film thickness of 100 nm (horizontal axis) is formed on the sidewall, a film thickness of about 110 nm (vertical axis) is formed on the bottom surface (Si surface). ２ =CF ２ (▲) indicates that a deposition film that does not easily adhere to the bottom surface (Si surface) (adheres thinly to the bottom surface (Si surface)) can be formed.

[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]

[0099] Generally, in the 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 the etching process. The present disclosure provides a c-C deposition film by forming a deposition film using a deposition gas containing hydrofluoroethylene such as 1,2-difluoroethylene or 1,1-difluoroethylene. ４ F ８ , or C ３ F ６ Compared to the deposition film formed using the method, the deposition film is thinly attached to the bottom surface of the recess formed by the etching process, and can be evaluated as being superior, particularly in Si deep trench processing (Bosch process).

[0100] (5) Development of a high-efficiency, low-GWP gas for TSVs using a 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 a Poly-Si film.

[0101] A digital twin was used to explore low GWP gases for high-efficiency TSV. A digital twin is a virtual (but alternate reality with the same effects as reality) object, system, or process that is 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 viewpoint, the deposition rate, which is the performance index of the deposition gas, is higher than that of existing c-C ４ F ８ As a result, we found a candidate gas with a GWP of less than 1. ３ F ６ , CHF=CHF, CH ２ =CF ２ was selected as a candidate for alternative gas.

[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 effects 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] In the experiment, the same type of experimental equipment (Figure 3) as that used for TSV processing in mass production was used to deposit a protective film on the Poly-Si film and collect 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] FIG. 4 shows a diagram in which a digital twin was constructed using a predictive model and the distribution of deposition rate (DR) was calculated.

[0108] In Fig. 4, the vertical axis represents the deposition rate value, and the horizontal axis represents the gas species. When the results of this virtual experiment were verified using an actual experimental device, the results showed that CHF = CHF and CH ２ =CF ２ The alternative gas candidate is c-C ４ F ８ , and C ３ F ６ It was revealed that the deposition rate was high compared to the conventional method (Fig. 4).

[0109] In general, the search for alternative gases is basically based on the reference gas (c-C, which is currently used as a deposition gas). ４ F ８ The approach adopted is to find a local optimum around the conditions used in the previous study. By using a digital twin, gas exploration can be carried out over a wide range of conditions, making it possible to find the global optimum and shortening the experiment time from 245 hours to around 30 minutes.

[0110] The maximum deposition rate (DR) is ２ =CF ２ >CHF=CFH>C ３ F ６ ≒ c-C ４ F ８ The maximum value of DR was c-C ４ F ８ , and C ３ F ６ In contrast, CH ２ =CF ２ , and CHF=CFH were predominant (Fig. 4).

[0111] FIG. 5 is a diagram showing that the apparatus 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 species (Figure 5). ４ F ８ , and C ３ F ６ It was found that, among the equipment parameters, the ICP power and gas flow rate affect the deposition rate (DR) for FC gases. ２ =CF ２ In the HFC system, 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 (effective in reducing environmental impact) for high-efficiency TSV.

[0113] (6) Development of a deposition method for adjusting the deposition rate (DR) FIG. 6 shows an experiment for forming a deposition film.

[0114] Using a quadrupole mass spectrometer (QMS), the deposition gas (CH ２ =CF ２ ) radicals and the ion density were measured.

[0115] QMS measurement conditions at this time: Measurement mode: RGA mode (blocks positive ion inflow) Orifice size: 100 μmφ Electron energy for ionizing neutral particles: 70 eV Measurement mass number range: 1≦m / z≦150

[0116] Experimental apparatus parameters (variables) were selected, and under those conditions, a deposition film was deposited on a Poly-Si film using the experimental apparatus, and the deposition rate (DR) was collected.

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

[0118] Deposition gas (CH ２ =CF ２ etc.) in the range of 2.5 times the molecular weight (CH ２ =CF ２ The radical intensities of mass numbers in the range of m / z (1≦m / z≦150) are 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 QMS is corrected.

[0119] The relative intensity was calculated by dividing the radical intensity of the desired m / z of the deposition gas by the sum of the radical intensities of the mass numbers in the range of 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 dependency of the QMS measurement sensitivity.

[0121] The radical intensity 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 FIG. 6, a quadrupole mass spectrometer (QMS) EQP manufactured by Hiden Analytical Co. was attached to the side wall of the experimental apparatus. ２ =CF ２ Radicals (neutral particles) in the plasma were measured. The QMS measurement was performed in RGA mode by applying a positive voltage to prevent positive ions from flowing into the QMS, and only neutral particles were taken in through a 100 μmφ orifice.

[0123] The amount of ionized particles was measured for each mass number (m / z) by bombarding the captured neutral particles with electrons accelerated at 70 eV. m represents the molecular weight of the neutral particle being measured, and z represents the valence of the particles ionized in 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 dependency of the measurement sensitivity of QMS.

[0125] FIG. 7 shows the horizontal axis: (CH ２ =CF ２ 1 is a graph showing the correlation between the relative intensity of m / z=64*the square of the 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 is a 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: (CH ２ =CF ２ (relative intensity of m / z=64)*(square of source power density) Vertical axis: deposition rate (DR) [nm / min] Source power: inductively coupled plasma (ICP) power when deposition is performed.

[0129]

[0130]

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

[0132] (1) Area density of source power: W / cm ２ When the deposition rate (DR) is -6.8*10 １４ *x ２+1.5*10 ９ *x (2) Volume density of source power: W / cm ３ When the deposition rate (DR) is -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 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).

[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 is used to correct the mass dependency of the measurement sensitivity of the QMS.

[0136] m: molecular weight z: ionized charge 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] CH ２ =CF ２ (m / z=64) Relative intensity * (square of source power density) (1) Area of ​​dielectric window for plasma generation: 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 determined by the source power density (1) source power area density (unit: W / cm ２) is expressed as 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 determined by: (1) the source power density; (2) the source power volume density (unit: W / cm ３ ) is expressed as 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 deposition gas for TSV processing with low environmental impact (a low GWP gas for high-efficiency TSV), which can greatly contribute to reducing the environmental impact as three-dimensional 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. The deposition gas of claim 1 for use in plasma processing deposition in the manufacture of substrates with through silicon vias (TSVs).

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

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

6. The method according to claim 5, wherein the substrate is a substrate having a through silicon via (TSV), and the deposition gas according to claim 1 is used to perform the deposition of a plasma process.

7. The method according to claim 5, wherein the substrate is a substrate having a through silicon via (TSV), and the deposition is performed in a Bosch process using the deposition gas according to claim 1.

8. A method for performing deposition on a semiconductor manufacturing substrate, comprising: using the deposition gas described in item 1 above, and adjusting the deposition rate (DR) under the condition that satisfies the following formula: (1) areal density of source power: W / cm ２ When the deposition rate (DR) is -6.8*10 １４ *x ２ +1.5*10 ９ *x (2) Volume density of source power: W / cm ３ When the deposition rate (DR) is -6.6*10 １９ *x ２ +4.7*10 １１ *x x = (relative intensity of deposition gas) * (square of source power density) Relative intensity: This is the relative intensity obtained 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 the mass numbers 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 is used to correct the mass dependency of the measurement sensitivity of the QMS. m: molecular weight z: ionized charge in the QMS Source power density: Source power: inductively coupled plasma (ICP) power when performing deposition (unit: W) (1) Source power areal 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 ​​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 as follows: (1) The source power density is defined as the source power area density (unit: W / cm ２ ) is expressed as 4.0*10 －７ ≦ x ≦ 2.0 * 10 －６ or (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 having a gas ejection portion for the deposition gas according to claim 1.

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

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

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