KR19990072434A - Producting a thin film having a low dielectric constant using hdp-cvd - Google Patents

Abstract

The present invention uses a high density plasma-chemical vapor deposition (HDP-CVD) technique in a low pressure HDP-CVD chamber to deposit finely dispersed carbon doped thin films on a substrate surface. Provide a method. The method includes forming a high density plasma having a desired density of at least 10E16 ions / m ³ in an HDP-CVD chamber comprising an oxidant gas, an inert gas and one or more reactant species comprising carbon, silicon, and oxygen. do. The one or more reactant species may be selected from (1) methane (CH ₄ ) and silane (SiH ₄ ), (2) tetraethylorthosilicate (TEOS or Si (OC ₂ H ₅ ) ₄ ), (3) methyl-trimes Preference is given to being selected from the group consisting of oxysilanes (MTMS or SiCH ₃ (OC ₂ H ₅ ) ₃ ), and (4) phenyl-trimesoxysilane (PTMS or SiC ₆ H ₅ (OC ₂ H ₅ ) ₃ ) . The method further includes circulating the dissociated components of the reactant species to the substrate surface. After some of the dissociated components of the reactant species are adsorbed onto the substrate surface, a reaction to form a thin film takes place. The thin film is a finely dispersed carbon doped silicon oxide thin film such as SiO _x C _y having a low dielectric constant.

Description

How to form a low dielectric constant thin film using high density plasma-chemical vapor deposition technique {PRODUCTING A THIN FILM HAVING A LOW DIELECTRIC CONSTANT USING HDP-CVD}

Technical Field

FIELD OF THE INVENTION The present invention relates to deposition techniques for forming low K dielectric thin films, and in particular, high density plasma-chemical vapor deposition (HDP-CVD) techniques with reactive gas species containing carbon. And a deposition technique for forming a finely dispersed carbon-doped silicon oxide dielectric thin film having a low dielectric constant.

Description of related technology

1. Overview

Integrated circuit (IC) architectures have been rapidly decreasing as far as technological advances are permitted and are still on the decline. In short, it is desirable to produce smaller electronic components so that smaller electronic devices can be traded, which is important in that such devices include personal computers. A limitation on IC size reduction is that the parasitic effects associated with interconnects interconnecting transistors hinder the competitive technical desire to form faster digital circuits. Faster digital circuits can be formed by lowering the RC time constant of the wiring (called the interconnect) or all of its transistors. RC time constants associated with these parts increase as their structural size decreases. At the same time, it is desirable to produce novel dielectric films with better stress control and thermal stability and lower moisture adsorption.

A specific subject of the present specification is to address the reduction in capacitance associated with dielectrics used to separate interconnect portions from one another. In the state-of-the-art technique at the present time, several levels of interconnecting parts are needed to interconnect millions of circuit elements. Separation using insulator materials such as SiO ₂ has been used to separate wires between one level and between levels for the last 40 years. However, as wiring becomes denser, parasitic effects due to capacitive coupling negatively affect device performance and require insulators with lower dielectric constants.

2. Doping Silicon Dioxide (SiO ₂ )

Pure SiO ₂ thin films have a dielectric constant of approximately K = 4. SiO ₂ can be grown by oxidizing pure silicon using O ₂ or H ₂ O gas, or as reactants SiH ₄ / Ar / N ₂ O, SiH ₄ / Ar / NO, and / or SiH ₄ / Ar / O Deposition is carried out using chemical vapor deposition (CVD) techniques or plasma enhanced chemical vapor deposition (PE-CVD) techniques using reactants such as a _two- gas mixture. For interconnect dielectrics, a CVD process is mainly used. Deposition precursors produced from dissociated components of reactant gas species may include SiH ₃ , SiH ₂ and 0 groups created by electron impact dissociation of SiH ₄ and oxidants. However, anisotropic deposition is problematic when using this technique due to the possibility of the SiH ₃ and SiH ₂ precursors sticking together in silane discharges associated with meaningless surface diffusion.

Considerable research has been done in which SiO ₂ dielectric layers have been doped to lower the dielectric constant of the layer and improve other properties of the oxide layer. One doping technique using gas precursors involves substituting fluorine in the SiO ₂ matrix to produce layers that generally contain FxSiOy. The CVD technique used to produce thin films with the general formula FxSiOy additionally uses SiF ₄ as reactant gas, with one of the typical silanes (SiH ₄ ) and oxidizing gas mixtures mentioned above. The dielectric constant of a typical fluorinated silicon oxide film is lower than the dielectric constant for SiO ₂ , but at most has a dielectric constant of approximately K = 3.5 due to membrane stability and moisture adsorption problems.

Spin coating techniques have been used to produce carbon-containing SiO ₂ spin on glass (SOG) films with a dielectric constant @ K = 3.0. SOG films may be suitable for a large number of applications, including processing interconnect dielectrics. However, SOG processes have many manufacturing disadvantages. For example, SOG processes involve the use of liquids and cause material waste that needs to be discarded. SOG processes often produce membranes with high OH ⁻ concentrations. In addition, SOG processes often face temperature instability, tensile stress and moisture adsorption / desorption problems. Because of the problems associated with spin-on films and devices, some manufacturers may prefer low K CVD processes that allow, if available, to extend the usefulness of their device sets instead of taking action on the side of SOG techniques. will be.

In the past, organically doped SiO ₂ layers have also been deposited using the CVD process. One technique uses alternative precursors such as methyl silane (CH ₃ -SiH ₃ ) or phenyl silane (C ₆ H ₅ -SiH ₃ ) as substituents for SiH ₄ precursors. For this technique, the methyl group is only partially dissociated and some methyl component is in a bonded state with the silicon atoms in the oxide layer. The resulting CH ₃ -doped oxide layer has a dielectric constant of approximately K = 3. Another technique has used CH ₃ -SiH ₃ and H ₂ O ₂ as reactant species. In addition, organically doped silicon oxide films made by conventional CVD processes often face adhesion, moisture adsorption and temperature stability issues.

3. Dielectric layer free of doped or undoped SiO ₂

Another way to find materials that meet the above-mentioned objectives is to use a totally new material for the oxide layer instead of substitutionally doping SiO ₂ . Thin films of these materials comprising organic polymers (ie, polyamides, polyethylethers, etc.) have extremely low dielectric constants @ K = 2.5. While such K is attractive, dielectric layers based on organic polymers are not widely introduced into ICs. This is because the dielectric layer currently exists only at the research stage where it must meet the majority of integration requirements. However, research on such polymer materials continues to be conducted.

4. Plasma Enhanced CVD

Plasma enhanced CVD (PE-CVD) techniques have been used to deposit a silicon oxide layer as a dielectric. In a PE-CVD chamber, reactant gas species are partially dissociated as a result of collisions with electrons and other molecules and groups in the plasma. Although partial dissociation occurs in the plasma, many carbon atoms are in a bonded state with oxygen, silicon, hydrogen and other carbon atoms through the deposition process. Undesirably, most of these carbon atoms remain in association with these components after adsorption on the substrate and incorporation into the SiO ₂ film. The carbon atoms are not finely dispersed and do not separate in the SiO ₂ matrix, so that the quality of the film is not optimized.

PE-CVD includes tetraethylososilicate (TEOS or Si (OC ₂ H ₅ ) ₄ ), methyl-trimesoxysilane (MTMS or SiCH ₃ (OC ₂ H ₅ ) ₃ ), and phenyl-trimesoxysilane (PTMS Or various reactant gas species, including SiC ₆ H ₅ (OC ₂ H ₅ ) ₃ ). If n = 0-3 using a heavily diluted TEOS / O ₂ with precursors such as Si (OC ₂ H ₅ ) _n (OH) _4-n and Si (OC ₂ H ₅ ) _n O _4-n Oxide deposition produced good deposition conformation. This is at least partly due to the probability that the TEOS deposition precursors will stick to it much more than we would observe for the probability that SiO ₂ could stick. PE CVD has also been used to deposit PTMS due to similar results. As mentioned above, the introduction of carbon into SiO ₂ using either PE CVD has defects with the presence of the resulting undesirable hydrocarbon (CH bond) fragments and oxide layers of poor film stress properties.

PE-CVD processes use a relatively low density plasma compared to the high density techniques used in the methods of the present invention. The plasma contains ionized reactants that have mobility impinging on the electrons and other species inherent in the plasma at increasing rates as the density of the plasma increases. This collision decomposes the reactants and dissociates them into simpler components. The dissociation rate increases with the collision rate and consequently increases with the density of the plasma.

Conventional PE-CVD causes insufficient dissociation to produce desirable finely dispersed carbon doped silicon oxide films. The resulting films do not have a suitable carbon distribution where more atoms are sufficiently separated from the silicon oxide matrix.

1 and 2 show FTIR spectra of conventional CVD and SOG SiO x Cy films, respectively. Each FTIR spectrum shows significant peaks at 781 cm ⁻¹ and 1027 cm ⁻¹ . The peak at 781 cm ^-1 represents the CH bend frequency and the peak at 2974 cm ^-1 represents the CH stretch frequency. Each of them shows that a number of undesirable CH bond sites exist in the oxide film being studied. These data indicate that the carbon atoms are not separated in the SiO ₂ matrix as needed. Instead, many carbon atoms are bonded to hydrogen atoms that did not dissociate during the deposition process.

One object of the invention to Upington FIG carbon of SiO ₂ film to lower the dielectric constant of the SiO ₂ film. Another object of the present invention is the number and dangling bonds of H ^- and OH ^- that bind to carbon atoms at positions inherent in SiO x Cy to promote better film properties such as stress control and thermal stability. Is to reduce the number of

1 shows an FTIR spectrum of a conventional CVD SiO x Cy film.

2 shows the FTIR spectrum of a conventional spin-on-glass SiOxCy film.

3 is a schematic diagram of HDP-CVD in accordance with the present invention;

The present invention utilizes High Density Plasma-Chemical Vapor Deposition (HDP-CVD) techniques in an HDP-CVD chamber to have a low dielectric constant (eg, K = 2.9 to 3.2) on the substrate surface. By providing a first method of depositing a carbon doped silicon oxide thin film, these objects are achieved and the above-mentioned problems are solved. The method comprises that at least one reactant species has carbon as the component and one or at least one other reactant species has silicon as the component and one or at least one other reactant species has oxygen as the component Or introducing more reactant species into the HDP-CVD chamber. The method comprises a density higher than 10E 16, preferably in the range of 10E 16 to 10E 22, and specifically 10E 17 to 10E 19 ions in an HDP-CVD chamber comprising dissociated components of a plurality of reactant species. creating a high density plasma having a density in the range of / m ³ , allowing reactant species to be highly dissociated in the HDP-CVD chamber, and circulating the dissociated components adjacent to the substrate surface. . After some components of the reactant species are adsorbed on the substrate surface, reactions occur that produce a carbon doped SiO ₂ thin film comprising SiO x Cy on the substrate surface having desirable dielectric properties.

A second method is provided for depositing a low dielectric constant thin film on a substrate surface using an HDP-CVD technique in an HDP-CVD chamber. The method,

(1) methane and silane,

(2) tetraethyl orthosilicate (TEOS),

(3) methyl-trimesoxysilane (MTMS), and

(4) Phenyl-trimesoxysilane (PTMS)

Introducing one or more reactant species selected from the group consisting of into the HDP-CVD chamber, in which oxygen is introduced as a component of one of the reactant species of the reactant species, It is included as an individually introduced oxidant gas species as in the case of other reactants only. The method preferably is -10E 14 to 10E 16 ions / m ³ and higher than 10E 16 in an HDP-CVD chamber containing the dissociated components of the reactant species, preferably 10E 16 to 10E 22 ions / m ^3. And in the range of 10E 17 to 10E 19 ions / m ³ , the composition of the reactant species to produce a high density plasma having an ion density much larger than the ion density of PE-CVD and adjoining the substrate surface. Additional steps for circulating them. After some of the dissociated components are adsorbed on the substrate surface, reactions occur that produce a thin film on the substrate surface having desirable dielectric properties.

A third method of depositing a low dielectric constant thin film on an energized substrate at low pressure using a high density plasma chemical vapor deposition (HDP-CVD) technique in an HDP-CVD reaction chamber is provided.

(1) methane (CH ₄ ) and silane (SiH ₄ ), preferably oxidant,

(2) tetraethyl orthosilicate (TEOS, Si (OC ₂ H ₅ ) ₄ ),

(3) methyl-trimesoxysilane (MTMS, SiCH ₃ (OC ₂ H ₅ ) ₃ ), and

(4) Phenyl-trimesoxysilane (PTMS, SiC ₆ H ₅ (OC ₂ H ₅ ) ₃ )

At least one reactant gas selected from the group consisting of at least one inert gas into the HDP-CVD reaction chamber, at least one inert gas into the HDP-CVD reaction chamber, and a high density in the HDP-CVD chamber containing dissociated components of the reactant species Create a plasma, circulate the dissociated components close to the substrate such that some of the components are adsorbed on the substrate surface, and produce a carbon doped SiO ₂ thin film having a low dielectric constant on the substrate Energizing the substrate such that chemical reactions containing adsorption components of reactant species can occur, and removing adsorbed gas byproducts from the HDP-CVD chamber.

A semiconductor device of the present invention is a semiconductor substrate having a surface configured to deposit a thin film thereon in a high density plasma-chemical vapor deposition (HDP-CVD) chamber, depositing on the substrate surface in the HDP-CVD chamber. And a thin film on the substrate surface comprising SiO x C y. Preferably, the HDP-CVD chamber,

(1) methane (CH ₄ ) and silane (SiH ₄ ),

(2) tetraethyl orthosilicate (TEOS, or Si (OC ₂ H ₅ ) ₄ ),

(3) methyl-trimesoxysilane (MTMS, or SiCH ₃ (OC ₂ H ₅ ) ₃ ), and

(4) Phenyl-trimesoxysilane (PTMS, or SiC ₆ H ₅ (OC ₂ H ₅ ) ₃ )

It contains a high density plasma comprising one or more reactant species selected from the group consisting of.

Example

A preferred object of carrying out the process of the invention is to produce a thin film comprising carbon doped silicon-oxide. Such thin films have a lower dielectric constant than conventional SiO ₂ films and have good stress control and thermal stability. Such thin films have many uses and are especially used as dielectric layers between interconnect levels and also between metal contacts and silicon substrates in devices or integrated circuits based on MOS structured transistors. The presence of finely distributed carbon in the amorphous silicon oxide matrix is lower in the dielectric constant (K) of the material from approximately K = 4.0 for pure SiO ₂ films, preferably in the range of K = 2.5 to 3.5 A value in, causes it to decrease significantly, specifically to a value in the range K = 2.9 to 3.2. The thin film is preferably and advantageously made with a minimum number of dangling bonds and a minimum amount of H ^- and OH ^- bonding sites.

Referring to FIG. 3, a preferred method of practicing the present invention uses a high density plasma-chemical vapor deposition (HDP-CVD) system. The HDP-CVD system has a central chamber (2), in which the semiconductor or insulator substrate (4) is placed on a boat (6) that does not oppose the substrate and does not introduce impurities into the substrate. It is put on. Said boat 6 preferably comprises graphite or quartz. The central chamber 2 is composed of a material capable of withstanding a pressure as low as 1 millitorr or less, which is at least exhausted at such pressure and does not allow impurities to be introduced into the chamber or into a thin film on or above the chamber. have. The chamber is preferably composed of a ceramic material, but may be a metal such as stainless steel or aluminum. The central HDP chamber 2 has a lower operating pressure than the operating pressure for a conventional CVD or PE-CVD chamber. The pressure inherent in the HDP-CVD chamber is preferably 5 millitorr. The approximately 5 millitorr pressure inherent in the HDP chamber 2 is lower than the approximately 2 Torr pressure of a typical working PE-CVD chamber. The plasma density inherent in the HDP chamber 2 is higher than the plasma density for conventional CVD or PE-CVD, preferably higher than 10E 16, preferably in the range of 10E 16 to 10E 22, specific The range is 10E 17 to 10E 19 ions / m ³ . Such density may be higher than any of these preferred ranges. Typical operating pressures for PE-CVD chambers range from approximately 10E 14 to 10E 16 ions / m ³ .

Electron energy is preferably applied to the chamber 2 through the formation of a linear or near linear electric field or magnetic field (B). The electromagnetic field is sufficient to significantly improve the dissociation of reactant and oxidant gases in the central HDP-CVD chamber 2. The electromagnetic field applied in this way generates a high energy plasma in the chamber 2, thus causing such enhanced dissociation. The high dissociation energy caused by the rapid movement of electrons and ions in the electromagnetic field and the chamber 2, as well as the dense nature of the plasma itself, is initially a component of the reactant gas introduced into the chamber 2 It results in more collisions creating molecules, ions, elements and / or groups.

Specifically, the high ion density and electromagnetic field of the plasma inherent in the HDP chamber 2 leads to a more successful dissociation reaction between ions and molecules. Although the average free stroke is fixed by pressure, the improvement typically provided by the use of a magnetic field is caused by the longer stroke length of the ions before they are trapped at the electrode. Thus, the high ion density of the plasma of the present invention, together with the magnetic field, results in more overall collisions between reactants, components and ions that strike the plasma. The degree of dissociation in the plasma of the reactant and component species is thus increased because each ion encounters more collisions along the length of the ions prior to adsorption onto the substrate 4.

Specifically, the overall impingement number is improved in the HDP-CVD chamber 2 of the preferred embodiment of the present invention because, due to the applied magnetic field, the reactants and component species move in a circular, spiral or vortex fashion. This helical approach increases the stroke length of the reactant and component species, thereby increasing the overall number of collisions and dramatically improving dissociation in the chamber (2).

Preferably, the magnetic field is generated by a conductive coil for current transmission, for example linear and homogeneous, and induced along the length of the chamber 2. In this preferred embodiment, the charged electrons, ions and groups proceed in a spiral because the electron energy is converted into kinetic energy. These rapidly moving charged species then, when introduced into the chamber 2, break up with reactant species and oxidant gas, resulting in simpler ions and groups. Under optimal and desirable conditions. After most species face the plasma state over their stroke length, they dissociate extremely severely in the HDP chamber to the extent that they are the elemental and electronic components of the reactant species in the substrate 4.

The substrate 4 is preferably a silicon wafer, but may be composed of any semiconductor or insulator material. The silicon wafer may be P-type or n-type undoped or doped with various concentrations of dopants. The wafer may be polished or unpolished.

The preferred method comprises introducing a reactant gas into the central HDP chamber 2. In some embodiments of the present invention, only one reactant species is introduced into the working HDP-CVD chamber. In other embodiments, various reactant gas species are introduced into the working HDP chamber 2 through one or more intake holes 8. Each reactant may be introduced into the chamber 2 so that a specific mixture of reactants is introduced into the chamber 2 to maximize the deposition state while being individually controlled while being controlled by the gas inlet valve 10. Each reactant gas is individually valve controlled and the central chamber 2 is valve controlled such that an appropriate gas mixture is achieved in the central HDP chamber 2.

Some preferred reactants used in the preferred process of the present invention are (1) methane (CH ₄ ) and silane (SiH ₄ ), (2) tetraethylorthosilicate (TEOS, or Si (OC ₂ H ₅ ) ₄ ), ( 3) methyltrimesoxysilane (MTMS or SiCH ₃ (OC ₂ H ₅ ) ₃ ), and (4) phenyltrimesoxysilane (PTMS, or SiC ₆ H ₅ (OC ₂ H ₅ ) ₃ ). Common among these reactants is that they all contain carbon and silicon. Other reactant gases comprising carbon and silicon or containing one of these elements may be used, but the preferred method uses one reactant species or a combined reactant species, all of which include carbon and silicon. As the first reactant species in the preferred group does not contain oxygen, when the reactant species do not contain oxygen, oxygen gas is preferably introduced into the HDP-CVD chamber together with the reactant species. Some preferred oxidants include O ₂ and H ₂ O ₂ . After dissociation of the reactants in the plasma, the method of the present invention introduces carbon into an amorphous matrix of silicon and oxygen on the substrate surface. With the preferred reactants just mentioned, the oxidant and diluent gas are preferably introduced into the central chamber 2.

Typically, the non-reactant gas also enters the chamber 2 and acts as an initiator to facilitate and propel ionization and dissociation of the reactant gas in the plasma. Preferably, only inert gases such as argon are used because, unlike conventional CVD or plasma enhanced-CVD (PE-CVD) techniques, divalent diluents such as H ₂ or O ₂ are central This is because they can be easily dissociated in the HDP chamber, combined with carbon, or in foil on the substrate. It is typical that there is a greater degree of dissociation in the HDP chamber than in the PE-CVD chamber, i.

When the reactants are subjected to constant bombardment by electrons and other ions and groups in the chamber 2, in addition to the magnetic and / or electric fields inherent and applied to the central chamber 2, the chamber 2 and the substrate 4 It becomes extremely hot due to the adsorption of hot species in the plasma. Temperatures as high as 400 ° C. or higher can occur in the central HDP chamber 2 and in the substrate 4. Because of this naturally occurring high temperature, it is often not necessary to further heat the substrate 4 to improve the surface reactivity. However, in another embodiment of the present invention, the substrate 4 is heated by conventional means such as placing the substrate 4 in a furnace 12 or by bombarding the substrate with electrons or photons.

After a given reactant gas is mixed, the oxidant gas and diluent gas are introduced into the central HDP chamber 2 where a high density plasma is made using an electromagnetic field, and the next step is to dissociate the dissociated components of the reactant species into the surface of the substrate 4. To circulate. The rate at which gas reactants and their dissociated components reach the substrate surface depends on the mass transfer properties of the plasma and slightly on temperature. The HDP-CVD technique is an advantageous deposition technique that provides attractant gas-phase focusing and the resulting film.

Dissociated components of the reactant gas are circulated to abut the substrate. Such components are adjacent to the substrate where adsorption can occur easily. Before adsorption occurs, the components are sufficiently adjacent to the substrate so that a dipole-dipole or ion interaction can occur between the atoms and components that make up the substrate surface with a significant probability that these components can be bonded to the surface. Occupies a location adjacent to. This may or may not involve a collision between the components and the substrate surface.

At the plasma-substrate boundary, the adsorption of the reactant gas species, and the gaseous constituents of the oxidant gas, occurs when introduced into the chamber 2. Adsorption usually occurs when an atom or molecule has lost enough energy to impinge on one surface and bond components on that surface. Adsorption here occurs when the electrons are exchanged and the ionic force retains atoms or molecules.

Once adsorbed, the adsorbing atoms and adsorbing ions move along the surface and react to form a thin film on the substrate surface. In a preferred embodiment, high elemental adsorption is believed to be due to the high dissociation that occurs in the high density plasma. In this way, a small number of carbon bonding sites are occupied by undesirable groups such as H ^- and OH ^- because the carbon atoms are greatly removed until such carbon atoms are adsorbed on the surface. The preferred effect of reducing the number of dangling bonds in the membrane is also the result of using the method of the present invention. Thus, the carbon atoms occupy a position in the glass matrix that may otherwise be occupied by silicon atoms in pure amorphous SiO ₂ . In other words, the carbon atoms preferably occupy positions having oxygen atoms bonded to each of the four bond positions. Following the adsorption and reaction process, the gaseous by-products of the surface reaction are absorbed and removed from the HDP chamber 2.

There are many important advantages of the method of the present invention over conventional methods, but fall into two main categories. The first category of benefits includes those associated with using HDP-CVD techniques as opposed to PE-CVD or spin-coating. The second category includes those advantages achieved by using one or more reactants selected from the group consisting of CH ₄ / SiH ₄ , TEOS, PTMS and MTMS.

Using the HDP-CVD technique is extremely advantageous because the central chamber 2 contains an extremely dense ion plasma. Electron energy under low pressure conditions in the chamber and this high density of plasma result in high reactant dissociation, including the plasma entering the chamber. Specifically, the carbon and silicon atoms that make up the reactant deviate from the previously attached group with two consequences. First, gas phase focusing results in better stress control and thermal stability of the resulting thin dielectric film. Secondly, the free silicon, oxygen and carbon atoms are adsorbed on the substrate surface and react with them to remove attached groups, thereby resulting in less CH bond sites, less overall hydrogen content and less in the resulting thin dielectric film. Results in silanol content.

The use of methane / silane, TEOS, PTMS and / or MTMS as the reactant gas is extremely advantageous because each of them contains carbon. Carbon atoms dissociate from other molecular components of the reactant inherent in the HDP chamber. Thus, the carbon atoms become an important component in the oxide thin film. In fact, the presence of carbon atoms in the resulting film lowers the dielectric constant of the film from approximately K = 2.9 to K = 3.2. Moreover, the membrane has high stress control and is thermally stable. Furthermore, the carbon atoms are positive adsorption layer species and do not invade and erode the components or substrate of the thin film, whether or not combined with hydrogen.

Carbon doped SiO ₂ films are also advantageous over SiO _X F _y films made using the HDP-CVD technique and also have lower dielectric constants than typical SiO ₂ films. In contrast, in contrast to the carbon atoms of the present invention, fluorine atoms are coarse adsorbent layer species that invade and adversely affect interconnect materials in subsequent elevated temperature processes.

In summary, using the HDP-CVD technique as opposed to the PE-CVD technique results in a good film with few undesirable additive species such as H ^- and OH ^- due to the high dissociation in the chamber. Using methane / silane, TEOS, PTMS and / or MTMS or any of a wide variety of organic materials as reactant species with suitable oxidants in the plasma, if necessary, introduces carbon into the matrix of the plasma and the resulting thin film, Lowers the dielectric constant of the membrane without adversely affecting it.

Claims (5)

A method for depositing finely dispersed carbon doped silicon oxide thin films on a substrate surface using HDP-CVD techniques in a high density plasma-chemical vapor deposition (HDP-CVD) chamber, Introducing one or more reactant species comprising carbon, silicon and oxygen into the HDP-CVD chamber; Producing a high density plasma having a density higher than 10E 16 ions / m ³ in an HDP-CVD chamber comprising a plurality of dissociated components of the one or more reactant species; And Circulating the components to the substrate surface, wherein the components react with the substrate surface to react to produce a thin film comprising SiO _x C _y on the substrate surface How to include. The method of claim 1, wherein at least one reactant species of the one or more reactant species is: (1) methane and silane, (2) tetraethyl orthosilicate (TEOS), (3) methyl-trimesoxysilane (MTMS), and (4) Phenyl-trimesoxysilane (PTMS) Method selected from the group consisting of: A method for depositing finely dispersed carbon doped thin films on a substrate surface using HDP-CVD techniques in a high density plasma-chemical vapor deposition (HDP-CVD) chamber, (1) methane and silane, (2) tetraethyl orthosilicate (TEOS), (3) methyl-trimesoxysilane (MTMS), and (4) Phenyl-trimesoxysilane (PTMS) Introducing one or more reactant species from which at least one reactant species is selected from the HDP-CVD chamber; Creating a high density plasma having a density higher than 10E 16 ions / m ³ in an HDP-CVD chamber containing dissociated components of the one or more reactant species; And Circulating the components to the substrate surface, wherein the components react to adsorb the substrate surface to form a thin film on the substrate surface How to include. A method for depositing finely dispersed carbon doped thin films with low dielectric constant on energized substrate surfaces using HDP-CVD techniques in a high density plasma-chemical vapor deposition (HDP-CVD) reaction chamber. , Providing a substrate having a surface configured to deposit a thin film thereon in the HDP-CVD reaction chamber; (1) methane and silane, (2) tetraethyl orthosilicate (TEOS), (3) methyl-trimesoxysilane (MTMS), and (4) Phenyl-trimesoxysilane (PTMS) Introducing one or more reactant species selected from the group consisting of into the HDP-CVD chamber; Introducing at least one inert gas and an oxidant gas into the HDP-CVD reaction chamber; Applying an electromagnetic field to the HDP-CVD chamber to produce a high density plasma having a density higher than 10E 16 ions / m ³ in an HDP-CVD chamber containing dissociated components of the one or more reactant species; Circulating the components adjacent the substrate such that some components are adsorbed on the substrate surface; Energizing the substrate surface such that chemical reactions involving the adsorbed reactant species can occur to produce a thin carbon doped SiO ₂ film on the substrate; And Removing adsorbed gas byproducts from the HDP-CVD chamber How to include. A semiconductor substrate having a surface configured to deposit a thin film in a high density plasma-chemical vapor deposition (HDP-CVD) chamber; And A thin film deposited on the substrate surface in the HDP-CVD chamber and comprising SiO _x C _y Semiconductor device comprising a.