WO2011108456A1 - 低誘電率層間絶縁膜および低誘電率層間絶縁膜の成膜方法 - Google Patents
低誘電率層間絶縁膜および低誘電率層間絶縁膜の成膜方法 Download PDFInfo
- Publication number
- WO2011108456A1 WO2011108456A1 PCT/JP2011/054303 JP2011054303W WO2011108456A1 WO 2011108456 A1 WO2011108456 A1 WO 2011108456A1 JP 2011054303 W JP2011054303 W JP 2011054303W WO 2011108456 A1 WO2011108456 A1 WO 2011108456A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- insulating film
- dielectric constant
- interlayer insulating
- low dielectric
- film
- Prior art date
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02104—Forming layers
- H01L21/02107—Forming insulating materials on a substrate
- H01L21/02225—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer
- H01L21/0226—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process
- H01L21/02263—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process deposition from the gas or vapour phase
- H01L21/02271—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process deposition from the gas or vapour phase deposition by decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition
- H01L21/02274—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process deposition from the gas or vapour phase deposition by decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition in the presence of a plasma [PECVD]
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
- C23C16/22—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the deposition of inorganic material, other than metallic material
- C23C16/30—Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
- C23C16/44—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating
- C23C16/50—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating using electric discharges
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02104—Forming layers
- H01L21/02107—Forming insulating materials on a substrate
- H01L21/02109—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates
- H01L21/02112—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer
- H01L21/02123—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer the material containing silicon
- H01L21/02167—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer the material containing silicon the material being a silicon carbide not containing oxygen, e.g. SiC, SiC:H or silicon carbonitrides
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02104—Forming layers
- H01L21/02107—Forming insulating materials on a substrate
- H01L21/02109—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates
- H01L21/02203—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates the layer being porous
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02104—Forming layers
- H01L21/02107—Forming insulating materials on a substrate
- H01L21/02109—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates
- H01L21/02205—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates the layer being characterised by the precursor material for deposition
- H01L21/02208—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates the layer being characterised by the precursor material for deposition the precursor containing a compound comprising Si
- H01L21/02211—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates the layer being characterised by the precursor material for deposition the precursor containing a compound comprising Si the compound being a silane, e.g. disilane, methylsilane or chlorosilane
Definitions
- the present invention relates to a low dielectric constant interlayer insulating film and a method for forming a low dielectric constant interlayer insulating film.
- the wiring layer has been miniaturized along with the high integration of semiconductor devices.
- the influence of signal delay in the wiring layer is increased, and the increase in signal transmission speed is prevented. Problems have been pointed out. Since this signal delay is proportional to the resistance of the wiring layer and the wiring interlayer capacitance, it is required to reduce the resistance of the wiring layer and reduce the wiring interlayer capacitance in order to achieve high speed.
- the SiO2 film has a relative dielectric constant of 4.1 and the SiOF film has a relative dielectric constant of 3.7, but an SiOCH film or an organic film having a lower relative dielectric constant has been used.
- an insulating film (hereinafter referred to as a barrier film) having a diffusion barrier property and having few holes and voids is often formed around the copper wiring.
- This barrier film is also required to have a low dielectric constant while maintaining diffusion barrier properties without increasing the number of holes and voids (see Patent Document 1 and Patent Document 2).
- the insulating film such as the SiOCH film, the organic film, and the barrier film is subjected to processes such as an etching process, a cleaning process, and a polishing process. Therefore, for these treatments, adhesion is required so that the insulating films and the metal-insulating film do not peel off. Further, it is widely known that the adhesion is mainly caused by the mechanical strength of the insulating film (see Non-Patent Document 1 and Non-Patent Document 2). Further, in order to prevent the insulating film from being damaged, it is required that the mechanical strength including adhesion is high (see Patent Document 3). However, it has been pointed out that the mechanical strength decreases when holes or voids are formed in the insulating film.
- a low dielectric constant interlayer insulating film such as a SiOCH film achieves a low dielectric constant by providing many holes and voids.
- the conventional low dielectric constant interlayer insulating film has a problem that the barrier property of gas and metal is inferior because there are many holes and voids.
- the conventional low dielectric constant interlayer insulating film has a problem that the cohesive energy is weak and the adhesion with a film of another composition is inferior.
- barrier property and adhesion are inferior, it may cause insulation film breakdown, electromigration, stress migration, and the like, resulting in reduced wiring reliability.
- a first aspect of the present invention is a low dielectric constant interlayer insulating film formed by plasma CVD method and containing at least carbon and silicon, and the ratio of carbon to silicon is 2.5 or more. And a low dielectric constant interlayer insulating film having a relative dielectric constant of 3.8 or less.
- the ratio of carbon to silicon is preferably 3.0 or more.
- the relative dielectric constant is preferably 3.5 or less.
- the low dielectric constant interlayer insulating film of the present invention is preferably made of silicon, carbon, and hydrogen.
- a low dielectric constant interlayer insulating film forming method including a step of forming an insulating film material containing at least carbon and silicon by a plasma CVD method, wherein the insulating film material is a hydrocarbon.
- isobutyltrimethylsilane, diisobutyldimethylsilane, or 5-silaspiro [4,4] nonane as the insulating film material.
- a reduction in dielectric constant and improvement in barrier properties and adhesion can be satisfied at the same time, and the reliability is improved while suppressing dielectric breakdown, electromigration and stress migration. be able to.
- FIG. 1 is a schematic configuration diagram showing an example of a film forming apparatus used in an embodiment of the present invention.
- FIG. 2 is a graph showing the relationship between the relative dielectric constant, the ratio of carbon to silicon (C / Si ratio), and barrier properties.
- the low dielectric constant interlayer insulating film of this embodiment is formed by a plasma CVD method.
- a plasma CVD method When a multilayer wiring structure or the like is formed on a substrate, diffusion of at least one substance out of metal, moisture, and oxygen is performed. It is a film formed for the purpose of preventing. For example, it is used as a copper diffusion barrier film when copper is used as a wiring layer.
- the low dielectric constant interlayer insulating film is a film containing at least carbon and silicon, and specifically includes a SiCH film, a SiOCH film, a SiCN film, and the like.
- the ratio of carbon to silicon (element composition ratio) is 2.5 or more, and more preferably 3.0 or more.
- the upper limit value of the ratio of carbon to silicon is preferably 4.5 and more preferably 4.0.
- the low dielectric constant interlayer insulating film is preferably made of silicon, carbon, oxygen, nitrogen, and hydrogen, and more preferably made of silicon, carbon, and hydrogen.
- the relative dielectric constant is 3.8 or less, and more preferably 3.5 or less.
- the lower limit value of the relative dielectric constant is preferably 2.5, and more preferably 3.0.
- the film forming method of this embodiment is a method of forming an insulating film material by a plasma CVD method.
- the insulating film material the low dielectric constant interlayer insulating film to be formed has a carbon to silicon ratio of 2. Any material may be used as long as it is 5 or more and the relative dielectric constant is 3.8 or less. For example, the following materials can be used.
- insulating film materials it is particularly preferable to use isobutyltrimethylsilane, diisobutyldimethylsilane, or 5-silaspiro [4,4] nonane. Moreover, it is preferable not to use hydrocarbons as the insulating film material.
- the mixing ratio in the case of using a mixture of two or more kinds of insulating film materials is not particularly limited, and the obtained low dielectric constant interlayer insulating film has a carbon to silicon ratio of 2.5 or more and a relative dielectric constant. Any combination may be used as long as the rate is 3.8 or less.
- the elemental composition ratio of the low dielectric constant interlayer insulating film can be adjusted by using an insulating film material having a specific elemental composition ratio.
- the relative dielectric constant of the low dielectric constant interlayer insulating film is a physical property value that depends on the elemental composition ratio and the porosity.
- the porosity is preferably 0.17 or less, more preferably 0.16 or less, and most preferably 0.15 or less. Since it is ideal that the porosity is 0 from the viewpoint of improving barrier properties and adhesion, it is not necessary to set a lower limit value.
- a carrier gas can be added to the insulating film material during film formation.
- the gas fed into the chamber of the film formation apparatus and used for film formation may be a mixed gas in which a carrier gas is mixed in addition to a gas made of an insulating film material.
- the carrier gas includes oxygen-free gas, for example, nitrogen, hydrogen, etc., in addition to noble gases such as helium, argon, krypton, and xenon, but is not particularly limited thereto. Only one type of carrier gas may be used alone, or two or more types may be used, and the mixing ratio including the insulating film material is not particularly limited.
- the insulating film material and the carrier gas are gaseous at room temperature, they can be used as they are. If the insulating film material and the carrier gas are liquid at room temperature, they are used after being vaporized by bubbling using an inert gas such as helium, vaporized by a vaporizer, or vaporized by heating.
- an inert gas such as helium, vaporized by a vaporizer, or vaporized by heating.
- the plasma film forming apparatus 1 shown in FIG. 1 includes a chamber 2 that can be depressurized.
- the chamber 2 is connected to an exhaust pump 5 through an exhaust pipe 3 and an on-off valve 4.
- the chamber 2 is provided with a pressure gauge (not shown) so that the pressure in the chamber 2 can be measured.
- a pair of flat plate-like upper electrode 6 and lower electrode 7 that are opposed to each other are provided in the chamber 2, a pair of flat plate-like upper electrode 6 and lower electrode 7 that are opposed to each other are provided.
- the upper electrode 6 is connected to a high frequency power source 8 so that a high frequency current is applied to the upper electrode 6.
- the lower electrode 7 also serves as a mounting table on which the substrate 9 is mounted.
- a heater 10 is built in the lower electrode 7 so that the substrate can be heated.
- a gas supply pipe 11 is connected to the upper electrode 6.
- a film-forming gas supply source (not shown) is connected to the gas supply pipe 11, and a film-forming gas is supplied from the film-forming gas supply device. This gas is formed in the upper electrode 6. It flows out through the through-holes while diffusing toward the lower electrode 7.
- the film forming gas supply source includes a vaporizer for vaporizing the insulating film material and a flow rate adjusting valve for adjusting the flow rate, and a supply device for supplying a carrier gas.
- the gas flows through the gas supply pipe 11 and flows out from the upper electrode 6 into the chamber 2.
- the substrate 9 is placed on the lower electrode 7 in the chamber 2 of the plasma film forming apparatus, and the film forming gas is sent into the chamber 2 from a film forming gas supply source.
- a high frequency current is applied to the upper electrode 6 from the high frequency power source 8 to generate plasma in the chamber 2.
- an insulating film generated by the gas phase chemical reaction from the film forming gas is formed on the substrate 9.
- a substrate mainly made of a silicon wafer is used. However, other insulating films, conductive films, wiring structures and the like formed in advance may exist on the silicon wafer.
- ICP plasma in addition to the parallel plate type, ICP plasma, ECR plasma, magnetron plasma, high frequency plasma, microwave plasma, capacitively coupled plasma, inductively coupled plasma, etc. can be used. It is also possible to use a two-frequency excitation plasma that introduces a high frequency to the lower electrode.
- the film forming conditions in this plasma film forming apparatus are preferably in the following range, but are not limited to this because they differ depending on the insulating film material used.
- Insulating film material flow rate 20 to 100 cc / min (If 2 or more types, total amount)
- Carrier gas flow rate 0 to 50 cc / min Pressure: 1 Pa to 1330
- RF power 50 to 500 W, preferably 50 to 250 W
- Substrate temperature 400 ° C. or less
- Reaction time 1 second to 1800 seconds
- Film thickness 100 nm to 200 nm
- the ratio of carbon to silicon is 2.5 or more and the relative dielectric constant is 3.8 or less, so that the barrier property and adhesion can be improved.
- the low dielectric constant interlayer insulating film of the present embodiment does not generate voids and vacancies, and instead, many hydrocarbons are films. It will be taken in, and barrier property and adhesiveness can be improved. As a result, dielectric breakdown, electromigration and stress migration can be suppressed, and reliability can be improved.
- hydrocarbon is not used as the insulating film material. That is, all of the carbon mixed in the formed low dielectric constant interlayer insulating film is caused by the insulating film material containing silicon. As a result, carbon is uniformly mixed into the formed low dielectric constant interlayer insulating film, and the barrier property and adhesion can be further improved.
- hydrocarbons there are advantages that it is easy to optimize film forming conditions for each apparatus, and that a detector for managing volatile hydrocarbons is not necessary.
- a SiCH film was formed as a low dielectric constant interlayer insulating film by using a plasma CVD method.
- A is superior when compared with the SiCN film having a relative dielectric constant of 4.8, which has been conventionally used as a barrier film, and B is equivalent.
- the case where it was slightly inferior was C, and the case where there was no barrier property was D.
- the barrier property was evaluated by forming a copper electrode, measuring the current-voltage characteristics, and comparing the breakdown voltage.
- the adhesion was evaluated by a tape test, 100 grids of 1 mm square were prepared, and the magnitude of the adhesion was compared with the number of cells that were not peeled off.
- the ratio of carbon to silicon (C / Si ratio) was measured by X-ray photoelectron spectroscopy (XPS).
- the relative dielectric constant was measured by capacitance-voltage measurement using a mercury probe.
- the porosity was calculated from density measurement and film composition. Note that the low dielectric constant interlayer insulating film of the present invention is not limited to a SiCH film.
- Example 1 In Example 1, isobutyltrimethylsilane (iBTMS) was used as an insulating film material, and when a SiCH film was formed under conditions of a flow rate of 20 sccm, a pressure of 3 Torr, and a plasma output of 550 W, a SiCH film having a relative dielectric constant of 3.5 was obtained. It was. Table 1 shows the results of evaluating the ratio of carbon to silicon (C / Si ratio), porosity, barrier properties, and adhesion. From this result, it was found that in the low dielectric constant interlayer insulating film of Example 1, the C / Si ratio was large, so that the porosity was small. Moreover, it turned out that barrier property is equivalent to the existing one.
- iBTMS isobutyltrimethylsilane
- Example 2 uses diisobutyldimethylsilane (DiBDMS) as an insulating film material, and when a SiCH film is formed under conditions of a flow rate of 20 sccm, a pressure of 3 Torr, and a plasma output of 650 W, a SiCH film having a relative dielectric constant of 3.5 is obtained. It was. Table 1 shows the results of evaluating the ratio of carbon to silicon (C / Si ratio), porosity, barrier properties, and adhesion. From this result, it was found that in the low dielectric constant interlayer insulating film of Example 2, the C / Si ratio was large, so that the porosity was small. Moreover, it turned out that barrier property is equivalent to the existing thing, and adhesiveness is superior to the existing thing.
- DIBDMS diisobutyldimethylsilane
- Example 3 when an SiCH film was formed using diisobutyldimethylsilane (DiBDMS) as an insulating film material under the conditions of a flow rate of 20 sccm, a pressure of 3 Torr, and a plasma output of 450 W, a SiCH film having a relative dielectric constant of 3.0 was obtained. It was. Table 1 shows the results of evaluating the ratio of carbon to silicon (C / Si ratio), porosity, barrier properties, and adhesion. From this result, it was found that in the low dielectric constant interlayer insulating film of Example 3, the C / Si ratio was large, so that the porosity was small. Moreover, although the barrier property was slightly inferior to the existing one, it was found that the adhesion was excellent.
- DIBDMS diisobutyldimethylsilane
- Example 4 uses diisobutyldimethylsilane (DiBDMS) as an insulating film material, and when a SiCH film is formed under conditions of a flow rate of 20 sccm, a pressure of 3 Torr, and a plasma output of 850 W, a SiCH film having a relative dielectric constant of 3.8 is obtained. It was. Table 1 shows the results of evaluating the ratio of carbon to silicon (C / Si ratio), porosity, barrier properties, and adhesion. From this result, it was found that in the low dielectric constant interlayer insulating film of Example 4, the C / Si ratio was large, so that the porosity was small. Moreover, it turned out that both barrier property and adhesiveness are superior to the existing one.
- DIBDMS diisobutyldimethylsilane
- Example 5 uses 5-silaspiro [4,4] nonane (SSN) as an insulating film material, and when a SiCH film is formed under conditions of a flow rate of 20 sccm, a pressure of 1 Torr, and a plasma output of 100 W, a relative dielectric constant of 3.0 is obtained. A SiCH film was obtained.
- Table 1 shows the results of evaluating the ratio of carbon to silicon (C / Si ratio), porosity, barrier properties, and adhesion. From this result, it was found that in the low dielectric constant interlayer insulating film of Example 5, the C / Si ratio was large, so that the porosity was small. Moreover, it turned out that barrier property is equivalent to the existing thing, and adhesiveness is superior to the existing thing.
- SSN 5-silaspiro [4,4] nonane
- Example 6 In Example 6, when 5-silaspiro [4,4] nonane (SSN) was used as the insulating film material and a SiCH film was formed under the conditions of a flow rate of 20 sccm, a pressure of 1 Torr, and a plasma output of 250 W, the relative dielectric constant was 3.5. A SiCH film was obtained. Table 1 shows the results of evaluating the ratio of carbon to silicon (C / Si ratio), porosity, barrier properties, and adhesion. From this result, it was found that in the low dielectric constant interlayer insulating film of Example 6, the C / Si ratio was large, so that the porosity was small. Moreover, it turned out that both barrier property and adhesiveness are superior to the existing one.
- SSN 5-silaspiro [4,4] nonane
- Comparative Example 1 tetramethylsilane (4MS) was used as an insulating film material, and when a SiCH film was formed under conditions of a flow rate of 20 sccm, a pressure of 3 Torr, and a plasma output of 650 W, a SiCH film having a relative dielectric constant of 3.5 was obtained. It was. Table 2 shows the results of evaluating the ratio of carbon to silicon (C / Si ratio), porosity, barrier properties, and adhesion. From this result, it was found that the low dielectric constant interlayer insulating film of Comparative Example 1 had a low C / Si ratio and a high porosity. Moreover, it turned out that barrier property and adhesiveness are inferior to the existing one.
- 4MS tetramethylsilane
- Comparative Example 2 tetramethylsilane (4MS) was used as an insulating film material, and when a SiCH film was formed under conditions of a flow rate of 20 sccm, a pressure of 5 Torr, and a plasma output of 650 W, a SiCH film having a relative dielectric constant of 3.3 was obtained. It was. Table 2 shows the results of evaluating the ratio of carbon to silicon (C / Si ratio), porosity, barrier properties, and adhesion. From this result, it was found that the low dielectric constant interlayer insulating film of Comparative Example 2 had a low C / Si ratio and a high porosity. Moreover, it turned out that barrier property and adhesiveness are remarkably inferior to the existing one.
- tetramethylsilane (4MS) was used as an insulating film material, and when a SiCH film was formed under conditions of a flow rate of 20 sccm, a pressure of 5 Torr, and a plasma output of 650 W, a SiCH film having
- Comparative Example 3 uses a mixture of trimethylsilane (3MS) and ethylene at a flow rate ratio of 1: 1 as an insulating film material, and forms a SiCH film under conditions of a flow rate of 60 sccm, a pressure of 8.4 Torr, and a plasma output of 550 W. A SiCH film having a relative dielectric constant of 4.1 was obtained. Table 2 shows the results of evaluating the ratio of carbon to silicon (C / Si ratio), porosity, barrier properties, and adhesion.
- FIG. 2 shows the relationship between the relative dielectric constant, the ratio of carbon to silicon (C / Si ratio), and the barrier property based on the above examples and comparative examples. From FIG. 2, it was found that when the C / Si ratio> ⁇ 2.2358 ⁇ relative dielectric constant + 10.714 is satisfied, the barrier property is superior or equivalent to that of the conventional one.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- Power Engineering (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Computer Hardware Design (AREA)
- Manufacturing & Machinery (AREA)
- General Physics & Mathematics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Metallurgy (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Plasma & Fusion (AREA)
- Inorganic Chemistry (AREA)
- Formation Of Insulating Films (AREA)
- Internal Circuitry In Semiconductor Integrated Circuit Devices (AREA)
- Chemical Vapour Deposition (AREA)
Abstract
Description
本願は、2010年3月1日に、日本に出願された特願2010-044263号に基づき優先権を主張し、その内容をここに援用する。
例えば、SiO2膜は4.1、SiOF膜は3.7の比誘電率を有するが、さらに比誘電率の低いSiOCH膜や有機膜を用いるようになってきている。
本実施形態の低誘電率層間絶縁膜は、プラズマCVD法によって形成されるものであり、基板上に多層配線構造等を形成する際に、金属、水分、酸素のうち少なくとも1つの物質の拡散を防止することを目的として成膜される膜である。例えば、配線層として銅を用いた際の銅拡散バリア膜として用いられるものである。
低誘電率層間絶縁膜においては、珪素に対する炭素の比率(元素組成比)は2.5以上であり、3.0以上であることがより好ましい。珪素に対する炭素の比率の上限値としては、4.5が好ましく、4.0がより好ましい。
また、低誘電率層間絶縁膜は、珪素、炭素、酸素、窒素、水素から構成されていることが好ましく、珪素、炭素、水素から構成されていることがより好ましい。
低誘電率層間絶縁膜においては、比誘電率が3.8以下であり、3.5以下であることがより好ましい。比誘電率の下限値としては、2.5が好ましく、3.0がより好ましい。
本実施形態の成膜方法は、絶縁膜材料をプラズマCVD法によって成膜する方法であり、絶縁膜材料としては、成膜される低誘電率層間絶縁膜が、珪素に対する炭素の比率が2.5以上であり、かつ比誘電率が3.8以下であればどのようなものを用いても構わないが、例えば下記の材料を用いることができる。
また、絶縁膜材料としては、炭化水素を用いないことが好ましい。
なお、低誘電率層間絶縁膜の元素組成比は、特定の元素組成比を有する絶縁膜材料を使用することによって調節することができる。また、低誘電率層間絶縁膜の比誘電率は、その元素組成比と空隙率に依存する物性値である。一般に空隙率が大きいと、低誘電率層間絶縁膜の比誘電率は低下するとともに、バリア性及び密着性が劣化する。本発明の低誘電率層間絶縁膜においては、空隙率が0.17以下であることが好ましく、0.16以下であることがより好ましく、0.15以下であることが最も好ましい。空隙率は0であることがバリア性及び密着性の向上の点から理想的であるので、特に下限値を設定する必要はない。
この場合は、成膜装置のチャンバー内に送り込まれ、成膜に供されるガスが、絶縁膜材料からなるガスの他に、キャリアガスが混合された混合ガスとなることがある。もっとも、金属、水分、または酸素の拡散防止性を向上させるためには、キャリアガスを用いないことが望ましい。
図1に示したプラズマ成膜装置1は、減圧可能なチャンバー2を備え、このチャンバー2は、排気管3、開閉弁4を介して排気ポンプ5に接続されている。また、チャンバー2には、図示しない圧力計が備えられ、チャンバー2内の圧力が測定できるようになっている。チャンバー2内には、相対向する一対の平板状の上部電極6と下部電極7とが設けられている。上部電極6は、高周波電源8に接続され、上部電極6に高周波電流が印加されるようになっている。
また、上部電極6には、ガス供給配管11が接続されている。このガス供給配管11には、図示しない成膜用ガス供給源が接続され、この成膜用ガス供給装置からの成膜用のガスが供給され、このガスは上部電極6内に形成された複数の貫通孔を通って、下部電極7に向けて拡散しつつ流れ出るようになっている。
プラズマ成膜装置のチャンバー2内の下部電極7上に基板9を置き、成膜用ガス供給源から上記成膜用ガスをチャンバー2内に送り込む。高周波電源8から高周波電流を上部電極6に印加して、チャンバー2内にプラズマを発生させる。これにより、基板9上に上記成膜用ガスから気相化学反応により生成した絶縁膜が形成される。
基板9としては、主にシリコンウェーハからなるものが用いられるが、このシリコンウェーハ上にはあらかじめ形成された他の絶縁膜、導電膜、配線構造などが存在していてもよい。
絶縁膜材料流量 :20~100cc/分 (2種以上の場合は合計量である)
キャリアガス流量 :0~50cc/分
圧力 :1Pa~1330Pa
RFパワー :50~500W、好ましくは50~250W
基板温度 :400℃以下
反応時間 :1秒~1800秒
成膜厚さ :100nm~200nm
珪素に対する炭素の比率(C/Si比)の測定は、X線光電子分光(XPS)により行った。
比誘電率の測定は、水銀プローブを用いた容量-電圧測定により行った。
空隙率は、密度測定と膜組成から算出した。
なお、本発明の低誘電率層間絶縁膜は、SiCH膜に限定されない。
実施例1は、絶縁膜材料としてイソブチルトリメチルシラン(iBTMS)を用い、流量20sccm、圧力3Torr、プラズマ出力550Wの条件でSiCH膜を成膜したところ、比誘電率3.5のSiCH膜が得られた。珪素に対する炭素の比率(C/Si比)、空隙率、バリア性、密着性を評価した結果を表1に示す。
この結果から、実施例1の低誘電率層間絶縁膜においては、C/Si比が大きいため、空隙率が小さいことが分かった。また、バリア性が既存のものと同等であることが分かった。
実施例2は、絶縁膜材料としてジイソブチルジメチルシラン(DiBDMS)を用い、流量20sccm、圧力3Torr、プラズマ出力650Wの条件でSiCH膜を成膜したところ、比誘電率3.5のSiCH膜が得られた。珪素に対する炭素の比率(C/Si比)、空隙率、バリア性、密着性を評価した結果を表1に示す。
この結果から、実施例2の低誘電率層間絶縁膜においては、C/Si比が大きいため、空隙率が小さいことが分かった。また、バリア性は既存のものと同等であり、密着性は既存のものより優れていることが分かった。
実施例3は、絶縁膜材料としてジイソブチルジメチルシラン(DiBDMS)を用い、流量20sccm、圧力3Torr、プラズマ出力450Wの条件でSiCH膜を成膜したところ、比誘電率3.0のSiCH膜が得られた。珪素に対する炭素の比率(C/Si比)、空隙率、バリア性、密着性を評価した結果を表1に示す。
この結果から、実施例3の低誘電率層間絶縁膜においては、C/Si比が大きいため、空隙率が小さいことが分かった。また、バリア性は既存のものよりもわずかに劣るものの、密着性は優れていることが分かった。
実施例4は、絶縁膜材料としてジイソブチルジメチルシラン(DiBDMS)を用い、流量20sccm、圧力3Torr、プラズマ出力850Wの条件でSiCH膜を成膜したところ、比誘電率3.8のSiCH膜が得られた。珪素に対する炭素の比率(C/Si比)、空隙率、バリア性、密着性を評価した結果を表1に示す。
この結果から、実施例4の低誘電率層間絶縁膜においては、C/Si比が大きいため、空隙率が小さいことが分かった。また、バリア性、密着性ともに既存のものより優れていることが分かった。
実施例5は、絶縁膜材料として5-シラスピロ[4,4]ノナン(SSN)を用い、流量20sccm、圧力1Torr、プラズマ出力100Wの条件でSiCH膜を成膜したところ、比誘電率3.0のSiCH膜が得られた。珪素に対する炭素の比率(C/Si比)、空隙率、バリア性、密着性を評価した結果を表1に示す。
この結果から、実施例5の低誘電率層間絶縁膜においては、C/Si比が大きいため、空隙率が小さいことが分かった。また、バリア性は既存のものと同等であり、密着性は既存のものより優れていることが分かった。
実施例6は、絶縁膜材料として5-シラスピロ[4,4]ノナン(SSN)を用い、流量20sccm、圧力1Torr、プラズマ出力250Wの条件でSiCH膜を成膜したところ、比誘電率3.5のSiCH膜が得られた。珪素に対する炭素の比率(C/Si比)、空隙率、バリア性、密着性を評価した結果を表1に示す。
この結果から、実施例6の低誘電率層間絶縁膜においては、C/Si比が大きいため、空隙率が小さいことが分かった。また、バリア性、密着性ともに既存のものより優れていることが分かった。
比較例1は、絶縁膜材料としてテトラメチルシラン(4MS)を用い、流量20sccm、圧力3Torr、プラズマ出力650Wの条件でSiCH膜を成膜したところ、比誘電率3.5のSiCH膜が得られた。珪素に対する炭素の比率(C/Si比)、空隙率、バリア性、密着性を評価した結果を表2に示す。
この結果から、比較例1の低誘電率層間絶縁膜においては、C/Si比が小さく、空隙率が大きいことが分かった。また、バリア性、密着性ともに既存のものより劣っていることが分かった。
比較例2は、絶縁膜材料としてテトラメチルシラン(4MS)を用い、流量20sccm、圧力5Torr、プラズマ出力650Wの条件でSiCH膜を成膜したところ、比誘電率3.3のSiCH膜が得られた。珪素に対する炭素の比率(C/Si比)、空隙率、バリア性、密着性を評価した結果を表2に示す。
この結果から、比較例2の低誘電率層間絶縁膜においては、C/Si比が小さく、空隙率が大きいことが分かった。また、バリア性、密着性ともに既存のものより著しく劣っていることが分かった。
比較例3は、絶縁膜材料としてトリメチルシラン(3MS)とエチレンを流量比1:1で混合したものを用い、流量60sccm、圧力8.4Torr、プラズマ出力550Wの条件でSiCH膜を成膜したところ、比誘電率4.1のSiCH膜が得られた。珪素に対する炭素の比率(C/Si比)、空隙率、バリア性、密着性を評価した結果を表2に示す。
この結果から、比較例3の層間絶縁膜においては、C/Si比と空隙率がともに小さいため、比誘電率が4.1と大きく、低誘電率層間絶縁膜が得られなかった。また、バリア性は既存のものと同等であった。
図2より、C/Si比>-2.2358×比誘電率+10.714を満たすとき、バリア性が従来よりも優れているないし同等であることが分かった。
2・・・チャンバー
3・・・排気管
4・・・開閉弁
5・・・排気ポンプ
6・・・上部電極
7・・・下部電極
8・・・高周波電源
9・・・基板
10・・・ヒーター
11・・・ガス供給配管
Claims (7)
- プラズマCVD法によって形成され、少なくとも炭素と珪素を含む低誘電率層間絶縁膜であって、
珪素に対する炭素の比率が2.5以上であり、かつ比誘電率が3.8以下である低誘電率層間絶縁膜。 - 珪素に対する炭素の比率が3.0以上である請求項1に記載の低誘電率層間絶縁膜。
- 比誘電率が3.5以下である請求項1に記載の低誘電率層間絶縁膜。
- 金属、水分、酸素のうち少なくとも1つの物質の拡散を防止する請求項1に記載の低誘電率層間絶縁膜。
- 珪素、炭素、水素からなる請求項1に記載の低誘電率層間絶縁膜。
- プラズマCVD法によって少なくとも炭素と珪素を含む絶縁膜材料を成膜する工程を有する低誘電率層間絶縁膜の成膜方法であって、
前記絶縁膜材料として炭化水素を用いず、
成膜された低誘電率層間絶縁膜において、珪素に対する炭素の比率が2.5以上であり、かつ比誘電率が3.8以下である低誘電率層間絶縁膜の成膜方法。 - 絶縁膜材料としてイソブチルトリメチルシラン、ジイソブチルジメチルシラン、または5-シラスピロ[4,4]ノナンを用いる請求項6に記載の低誘電率層間絶縁膜の成膜方法。
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/582,029 US20120328798A1 (en) | 2010-03-01 | 2011-02-25 | Inter-low-permittivity layer insulating film, and method for forming inter-low-permittivity layer insulating film |
CN2011800117927A CN102906865A (zh) | 2010-03-01 | 2011-02-25 | 低介电常数层间绝缘膜及低介电常数层间绝缘膜的成膜方法 |
KR1020127024085A KR20130038810A (ko) | 2010-03-01 | 2011-02-25 | 저유전율 층간 절연막 및 저유전율 층간 절연막의 증착 방법 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2010-044263 | 2010-03-01 | ||
JP2010044263A JP2011181672A (ja) | 2010-03-01 | 2010-03-01 | 低誘電率層間絶縁膜および低誘電率層間絶縁膜の成膜方法 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2011108456A1 true WO2011108456A1 (ja) | 2011-09-09 |
Family
ID=44542109
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2011/054303 WO2011108456A1 (ja) | 2010-03-01 | 2011-02-25 | 低誘電率層間絶縁膜および低誘電率層間絶縁膜の成膜方法 |
Country Status (6)
Country | Link |
---|---|
US (1) | US20120328798A1 (ja) |
JP (1) | JP2011181672A (ja) |
KR (1) | KR20130038810A (ja) |
CN (1) | CN102906865A (ja) |
TW (1) | TW201144473A (ja) |
WO (1) | WO2011108456A1 (ja) |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2004526318A (ja) * | 2001-03-23 | 2004-08-26 | ダウ・コーニング・コーポレイション | 水素化シリコンオキシカーバイド膜を生産するための方法 |
WO2007132879A1 (ja) * | 2006-05-17 | 2007-11-22 | Nec Corporation | 半導体装置、半導体装置の製造方法及び半導体製造装置 |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6303047B1 (en) * | 1999-03-22 | 2001-10-16 | Lsi Logic Corporation | Low dielectric constant multiple carbon-containing silicon oxide dielectric material for use in integrated circuit structures, and method of making same |
EP1314531A1 (en) * | 2001-11-22 | 2003-05-28 | Synventive Molding Solutions B.V. | Helical heating element for an injection moulding device |
JP4900239B2 (ja) * | 2005-02-18 | 2012-03-21 | 日本電気株式会社 | 有機シリコン系膜の形成方法、当該有機シリコン系膜を有する半導体装置及びその製造方法 |
JP2006294671A (ja) * | 2005-04-06 | 2006-10-26 | Mitsui Chemicals Inc | 低誘電率炭化珪素膜の製造方法 |
JP5200371B2 (ja) * | 2006-12-01 | 2013-06-05 | 東京エレクトロン株式会社 | 成膜方法、半導体装置及び記憶媒体 |
JP5074059B2 (ja) * | 2007-02-28 | 2012-11-14 | 東京エレクトロン株式会社 | 層間絶縁膜および配線構造と、それらの製造方法 |
-
2010
- 2010-03-01 JP JP2010044263A patent/JP2011181672A/ja active Pending
-
2011
- 2011-02-25 KR KR1020127024085A patent/KR20130038810A/ko not_active Application Discontinuation
- 2011-02-25 US US13/582,029 patent/US20120328798A1/en not_active Abandoned
- 2011-02-25 TW TW100106345A patent/TW201144473A/zh unknown
- 2011-02-25 WO PCT/JP2011/054303 patent/WO2011108456A1/ja active Application Filing
- 2011-02-25 CN CN2011800117927A patent/CN102906865A/zh active Pending
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2004526318A (ja) * | 2001-03-23 | 2004-08-26 | ダウ・コーニング・コーポレイション | 水素化シリコンオキシカーバイド膜を生産するための方法 |
WO2007132879A1 (ja) * | 2006-05-17 | 2007-11-22 | Nec Corporation | 半導体装置、半導体装置の製造方法及び半導体製造装置 |
Also Published As
Publication number | Publication date |
---|---|
CN102906865A (zh) | 2013-01-30 |
TW201144473A (en) | 2011-12-16 |
JP2011181672A (ja) | 2011-09-15 |
KR20130038810A (ko) | 2013-04-18 |
US20120328798A1 (en) | 2012-12-27 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US9111761B2 (en) | Multi component dielectric layer | |
US6649495B2 (en) | Manufacturing method of semiconductor device | |
JP5567588B2 (ja) | 酸素含有前駆体を用いる誘電体バリアの堆積 | |
JP2011166106A (ja) | 半導体装置の製造方法及び半導体装置 | |
JP4812838B2 (ja) | 多孔質絶縁膜の形成方法 | |
US8349746B2 (en) | Microelectronic structure including a low k dielectric and a method of controlling carbon distribution in the structure | |
US8212337B2 (en) | Advanced low k cap film formation process for nano electronic devices | |
WO2007061134A1 (ja) | 多孔質絶縁膜の形成方法、半導体装置の製造装置、半導体装置の製造方法及び半導体装置 | |
JP5317089B2 (ja) | 成膜方法および絶縁膜 | |
JP2007221039A (ja) | 絶縁膜および絶縁膜材料 | |
JP3486155B2 (ja) | 層間絶縁膜の形成方法 | |
US10301719B1 (en) | Amorphous hydrogenated boron carbide low-k dielectric and method of making the same | |
JP5505680B2 (ja) | 絶縁膜材料、この絶縁膜材料を用いた成膜方法および絶縁膜 | |
WO2011108456A1 (ja) | 低誘電率層間絶縁膜および低誘電率層間絶縁膜の成膜方法 | |
JP2015106572A (ja) | シリコン窒化膜の形成方法及びシリコン窒化膜 | |
JP2008218507A (ja) | 層間絶縁膜および配線構造と、それらの製造方法 | |
JP5750230B2 (ja) | 炭窒化珪素膜及び炭窒化珪素膜の成膜方法 | |
JP2008263022A (ja) | 絶縁膜材料、この絶縁膜材料を用いた成膜方法および絶縁膜 | |
JP5607394B2 (ja) | 層間絶縁膜の成膜方法および層間絶縁膜 | |
JP2002305242A (ja) | 半導体装置の製造方法 | |
JP2006294671A (ja) | 低誘電率炭化珪素膜の製造方法 | |
JP2007318070A (ja) | 絶縁膜材料、この絶縁膜材料を用いた成膜方法および絶縁膜 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 201180011792.7 Country of ref document: CN |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 11750566 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 13582029 Country of ref document: US |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
ENP | Entry into the national phase |
Ref document number: 20127024085 Country of ref document: KR Kind code of ref document: A |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 11750566 Country of ref document: EP Kind code of ref document: A1 |