TW525268B - Nanoporous dielectric films with graded density and process for making such films - Google Patents

Abstract

The present invention relates to nanoporous dielectric films and to a process for their manufacture. A substrate having a plurality of raised lines on its surface is provided with a relatively high porosity, low dielectric constant, silicon containing polymer composition positioned between the raised lines and a relatively low porosity, high dielectric constant, silicon containing composition positioned on the lines.

Description

525268 A7 B7 V. Description of the invention (1 Reference to the related application, the strict application of this application, Wang Zhang's power of US Provisional Patent Application No. 60 / 043,261, applied on April 17, 1997, this application is also in the application Part of the patent application No. 09 / (M6,474) filed on the 25th of the following year is continued, which is incorporated herein by reference. FIELD OF THE INVENTION The present invention relates to nanoscale microporous dielectrics. Thin film and a method for manufacturing the thin film. This thin film can be used in the manufacture of integrated circuits. The description of the prior art is used in the manufacture of integrated circuits. With the appearance size of 0.25 microns and less, the interconnection with RC delay, power Consumption and crosstalk related issues have become more obvious. The integration of low dielectric constant (K) materials for interlayer dielectric (ILD) and intermetal dielectric (IMD) applications can partially alleviate these problems, but various κ The choice of materials lower than the compact silica currently used has disadvantages. The development of most low-K materials focuses on K> 3 glass rotation (S0G) and fluorinated plasma CVD (chemical vapor deposition) Si02. Many organic and Kappa In the range of 2.2 to 3.5, however, these have many problems, including low thermal stability, poor mechanical properties including low glass transition temperature (T), sample degassing, and long-term reliability issues. Another method used Nai Meter-level microporous silica can have a dielectric constant ranging from 1 to 3 for the entire sample. Microporous silica is attractive because it uses precursors like SOG and CVD Si02 (such as TEOS, Tetraethoxysilane) and the ability to carefully control the pore size and size distribution. Except -4-This paper size applies to China National Standard (CNS) A4 (210 X 297 binding)

Line 525268 A7 B7 V. Description of the invention (2) " In addition to low dielectric constant, nano-scale microporous silica also provides other advantages of microelectronic devices, including thermal stability up to 900 ° C, small aperture (& Microelectronic appearance), materials widely used in the semiconductor industry, the use of silica and precursors (such as TEOS), the ability to change the dielectric constant over a wide range, and the use of tools similar to conventional SOG processing Perform coating. Although high porosity tends to result in a lower dielectric constant than corresponding compact materials, it can introduce additional compositions and procedures compared to denser materials. Material issues include the need for all holes to be significantly smaller than the apparent dimensions of the circuit, the strength to decrease with porosity, and the role of surface chemistry in dielectric constant and environmental stability. Density (or conversely, porosity) is a nano-scale microporous silica parameter that primarily controls dielectric importance. The properties of nano-scale microporous silicas can be varied in a continuous spectrum from the maximum degree of air gaps with a porosity of 100% to tight silicas with a porosity of 0%. As the density increases, the dielectric constant and mechanical strength increase but the pore size decreases. The proposed optimal density range for semiconductor applications is not the extremely low density associated with K ~ 1, but high density that produces high strength and smaller pore sizes. Nano-sized microporous silica thin films can be prepared by using a mixture of a solvent and a silica precursor, wherein the mixture can be coated on a silicon wafer by conventional methods such as spin coating and dip coating. The precursor is polymerized after coating, and the resulting layer is strong enough so that it does not shrink during the drying process. Film thickness and density / dielectric constant can be independently controlled using a mixture of two solvents with very different volatility. Evaporate more volatile solvents during and immediately after the precursor coating. Silica precursors, generally partial hydrolysis and condensation products of TEOS, are chemically and / or thermally polymerized until they form a gel layer. -5- This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) 525268 A7 B7 5. Description of the invention (3) Then the second solvent is removed by increasing the temperature. Assuming no shrinkage occurs after gelation, the final film's density / dielectric constant can be fixed by the low-volatility solvent-to-dream stone volume ratio. EP patent application EP 0 775 669 A2 shows a method of making nano-scale microporous silica films with uniform density throughout the thickness of the film ', which is incorporated herein by reference. The preferred method for making nano-scale microporous dielectrics is through the use of sol technology. As a result of the growth and interconnection of solid particles, a sol, a colloidal suspension of solid particles in a liquid, changes into a gel. One theory is that through continuous reactions in the sol, one or more molecules in the sol can finally reach a huge size, so it forms a solid network structure that essentially spreads the entire sol. At this point, the so-called gel point is a kind of gel. By this definition, a gel is a substance containing a continuous solid state structure contained in a continuous liquid phase. When the architecture is microporous, the term "gel" as used herein refers to an open-pored solid structure contained in a microporous fluid. It would be desirable to make a nano-grade microporous silica with a relatively low density and a low dielectric constant as an insulator between metal wires, and a high-density, strong microporous layer at the top of the wire on the top of the wire. Basically, this can be achieved by multiple coatings using precursors with different solvent / silica ratios. However, this method is costly because multiple coating and drying / baking steps must be used. SUMMARY OF THE INVENTION The present invention provides a multi-density nano-scale microporous dielectric coated substrate comprising a substrate, a plurality of raised lines on the substrate, and a single monolithic nano-scale microporous silicon-containing polymer composition Layer on the substrate, where the layer includes a gradation density, high porosity, and low dielectric constant between raised lines. This paper is sized for China National Standard (CNS) A4 (210X 297 mm) ^ 5268 A7 _____________ B7 V. Invention ^ 1 ~ ---- The first zone of the nano-sized microporous polymer composition containing sintered nanometers and the second zone are located in the two-stage density, low porosity, high dielectric constant, nanometer Meter-level micro. The second region composed of the silicon polymer composition, wherein the difference between the average refractive index of the second region and the average refractive index of the first region is about 0.03 to about 0.06. The present invention also provides a semiconductor device including a substrate, which includes a substrate with a raised convex line on the substrate, and a single-piece nano-level micro-hole. The silicon polymer composition layer is on a substrate, wherein the layer includes a first region composed of H-class grading densities, high porosity, low dielectric constant, and nano-scale microporous hard polymer composition at the convex line, And a second region composed of a graded density, low porosity, high dielectric constant, nano-scale micropores containing poly-5 composition on the top of the line, wherein the average refractive index of the second region and the first region The difference between the average refractive indices of the zones is about 0.000 to about 0.06. The present invention also provides a method for forming a multi-density nano-scale microporous dielectric coating on a substrate having raised pattern lines, which comprises a) combining at least one alkoxysilane with a relatively highly volatile solvent composition, The solvent composition with relatively low volatility and the optional water are blended, thus forming a mixture and causing partial hydrolysis and partial condensation of the alkoxysilane; b) coating the mixture on a substrate having raised pattern lines, The mixture is placed between the lines and on the line, while at least a portion of the relatively volatile solvent composition is distilled off; c) the mixture is exposed to water vapor and alkali vapor; and d) the vaporization is quite low Solvent composition, so a single monolithic nano-scale microporous silicon-containing polymer composition layer is formed on the substrate, and this layer covers the paper size and applies the Chinese National Standard (CNS) A4 specification (210X 297 mm) 525268 A7 " ―1-B7 V. Description of the invention (1) > Included in the raised line is a composition with a graded density, high porosity, low dielectric constant, nano-scale micropore-containing composition The first A region, and a second region composed of a graded density, low porosity, high dielectric constant, nano-sized microporous silicon-containing polymer composition, located on the top of the salty line, where the average refraction of the second region The difference between the refractive index and the average refractive index of the first region is about 0.03 to about 0.06. It has now been found that nano-scale microporous silicon films can be made in two density regions. One can be made between metal wires and contains a very low density Nano-level microporous silicon with low dielectric constant insulators, and very high density, high dielectric constant, and denser pore layers are formed on the top of the wires. The dielectric constant of the insulator can be controlled by silica oligomers ( The number and type of alkoxy groups on the dream polymer) are controlled. These scorching oxygen groups at the special point are removed in the program to obtain low density and low dielectric on some films in the trench between metal wires. Electrical constants. Brief description of the figure. Figure 1 is a graphic representation of a substrate with a metal line pattern. Figure 2 is a diagram of a patterned substrate coated with a firing-based silicon firing composition before the reaction. Figure 3 shows the patterned and Graphic illustration of the coated substrate after the reaction. Detailed description of specific examples The present invention forms a reaction product of at least one alkoxysilane and a relatively highly volatile solvent composition, a relatively low volatility solvent composition, optionally water, and optionally a catalytic amount of an acid The reaction product is coated on a substrate with raised lines such as metal or oxide lines. In this way, the blend will be applied between the line and the top of the line. During the reaction product coating process Paper size applies to China National Standard (CNS) A4 (210 X 297 mm) ------

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Line 525268 A7 _B7_— _ 5. In the description of the invention (6) or immediately after coating, the highly volatile solvents are distilled off. The reaction product is further hydrolyzed and condensed until it forms a gel layer and the portion on the top of the line shrinks. The metal wire supports this gel and prevents the gel from shrinking between the wires, so a relatively low density, high porosity, and low dielectric constant silica is produced between the wires. However, the gel on the top of the line is not so supported and shrunk. This reduction produces a relatively high density, low porosity, and high dielectric constant silica on the wire. Assuming no shrinkage occurs after gelation, the density / dielectric constant of the top film can be fixed by the volume ratio of the low-volatile solvent to silica. Then increase the temperature to remove the second solvent. Alkoxysilanes useful in the present invention include these compounds having the formula:

R

I

R-Si-R

I

R wherein at least two R groups are independently (^ to C4 alkoxy and if there is any remaining portion, it is independently selected from the group consisting of hydrogen, alkyl, phenyl, halogen, and substituted phenyl. For the purposes of this invention, the term alkoxy includes any other organic group that can be easily separated from silicon by hydrolysis at temperatures near room temperature. The R group can be ethylene glyc6xy or propylene Propylene glycoxy or the like, but preferably all four feet are methoxy, ethoxy, propoxy or butoxy. The best oxy-silicon includes not only tetraethoxy Silane (TEOS) and tetramethoxysilane. The paper size is applicable to the Chinese National Standard (CNS) A4 (210 X 297 mm) 525268 A7 _ —_B7_ V. Description of the invention (7) Phenoxy dream burning system and volatilization Solvent composition with relatively high properties, solvent composition with low volatile phase S, water as appropriate, and a catalytic amount of acid as the case may be. The water system is included to provide a medium for hydrolyzing alkoxysilanes. A relatively high volatility solvent composition is a A solvent composition which evaporates at a temperature significantly lower than that of a solvent composition having a relatively low volatility. A solvent composition having a relatively high volatility preferably has a boiling point of about 12.0 or lower, preferably about 100 ° C or Lower. Suitable high-volatile solvent compositions include not only methanol, ethanol, n-propanol, isopropanol, n-butanol, and mixtures thereof. Other highly volatile solvent compositions that are compatible with other components may be It is easily determined by those skilled in the art. A solvent composition having a relatively low volatility is a solvent composition which can evaporate at a temperature higher than, and preferably significantly higher than, a solvent composition having a relatively high volatility. Volatility The boiling point of the relatively low solvent composition is preferably about 175 t or more, preferably about 200 C or higher. Suitable low-volatile solvent compositions include not only alcohols and polyols, but also glycols such as ethylene glycol Alcohol, -butanediol, 1,5-pentanediol, ι, 2,4-butanetriol, ι, 2,3-butanetriol, 2-fluorenyl-propanediol, 2-(# Aminomethyl) ) -I, 3-propanediol, ι, 4,1,4-butanediol, 2-methyl-1,3-propanediol, tetra Ethylene glycol, triethylene glycol, monomethyl ether, glycerin and mixtures thereof. Other solvent compositions with relatively low volatility which are compatible with other components can be easily determined by those skilled in the art. The acid is used to catalyze the reaction of alkoxysilane with a highly volatile solvent composition, a relatively low volatility solvent composition, and water. Suitable acids are nitric acid and compatible and volatile organic acids, which can be At Procedure-10- This paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 525268 A7 ___ B7 V. Description of the invention (8) · ~ '' Evaporate from the reaction products obtained under the operating conditions without Impurities are introduced into the reaction product. The alkoxysilane component is preferably present in an amount of from about 3% to about 50% by weight of the total blend. The preferred range is from about 5% to about 45% by weight, and the most preferred range is from about 10% to about 40% by weight. Highly volatile solvent composition ingredients are preferably present in an amount of 20% by weight per scoop. To about 90% by weight. A preferred range is from about 30 weight. / ❶ to about 70 weight / >, preferably from about 40% by weight to about 60% by weight. The low volatility composition is preferably present in an amount of from about 1% to about 40% by weight of the total blend. The preferred range is from about 3% to about 30% by weight, and the most preferred range is from about 5% to about 20% by weight. The molar ratio of water to burnt is preferably from about 0 to about 50. The preferred range is from about 0.1 to about 10, and the most preferred range is from about 0.05 to about 1.5. The acid is present in a catalytic amount that can easily be determined by those skilled in the art. Therefore, the molar ratio of yakisoba is preferably from about 0 to about 02, more preferably from about 0.001 to about 0.05, and most preferably from about 0.05 to about 002. Then, the composition containing calcined oxygen is calcined on a substrate having pattern lines on the surface and a dielectric film is formed on the surface, as shown in Figs. 丨 and 2 'with the silica precursor composition layer 6 A substrate 2 having an array of pattern lines 4 is coated. The layer 6 is applied fairly evenly between and on the lines 6. The line is lithographically etched and may be made of metal, oxide, nitride, or oxynitride. Suitable materials include silica, silicon nitride, silicon nitride, silicon nitride, copper, copper alloy, copper, copper alloy, tungsten, and oxynitride. These lines form the conductors or insulators of the integrated circuit. -11-This paper size applies to China National Standard (CNS) A4 (210X 297mm) 525268

The highly volatile layer was then partially evaporated. In a matter of seconds or seconds, which causes the film to shrink, the volatile solvent evaporates. At this time, the film is a silica precursor and a low volatility agent, a viscous liquid. Optionally increase the temperature slightly: speed up this step. This temperature is in the range from about 80r. Car range; k is in the range from about 20C to about 50C, and more preferably from about 200C. . To about 35T: within the range. Typical substrates are these suitable for processing into integrated circuits or other microelectronic devices. Substrates suitable for use in the present invention include not only semiconductor materials such as gallium arsenide (GaAs), silicon, and silicon-containing compositions such as crystalline silicon, polycrystalline silicon, amorphous silicon, silicon oxide, silicon dioxide, silicon dioxide (S102 ) And mixtures thereof. Raised lines on the substrate surface, such as metal, oxide, nitride, or oxynitride lines, can be formed by the well-known lithographic etching technique. The lines are generally closely spaced from each other at a distance of about 20 micrometers or less, preferably J micrometers or less, and more preferably from a distance of about 0.05 to about 1 micrometer. The coating is then exposed to water vapor and alkali vapor. The steam can be introduced first, and then steam, or both steam and alkaline steam. This water vapor causes continuous hydrolysis of the alkoxy groups of the alkoxysilane, and the alkali catalyzes the hydrolyzed alkoxysilane to undergo a condensation reaction and is used to increase the molecular weight until the coating gels, and finally increase the gel strength. The coating between the wires is pressed and supported by the wires' so that it does not substantially shrink and forms a substance with a relatively low density, high porosity, and low dielectric constant. The silicon-containing polymer composition between the threads preferably has from about 1.1 to about 2.5, preferably from about 1.1 to about 2.2, and most preferably from about 1.5 to about 2.0 Dielectric constant. The pore size ranges from about 2 nm to about 200 nm, preferably from about 5 nm to about 50 nm, and most preferably from about -12- This paper size applies to China National Standard (CNS) A4 specifications ( 210X 297 mm)

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525268 A7 Description of the invention (100 micrometers to about 30 micrometers. The density of the pores containing the silicon-containing composition ranges from Ά 0 · 1 to about i 2 g / cm 2, preferably from about 0 25 Up to about 1 g / cm2, preferably from about 0.4 to about 0.8 g / cm2. The coating on the wire is not pressed, so it shrinks and thickens to a low porosity substance. If the condensation rate is much faster than Hydrolysis, a large amount of alkoxy groups will remain after the gel point. A slight amount of hydrolysis will occur, and then the film will not shrink and maintain the same thickness as the coating step. Continuous exposure to alkaline water vapor will cause continuous hydrolysis of the alkoxy groups The formation of silanols and volatile alcohols. These product alcohols leave the coating film, causing the area of the line to shrink. On the contrary, the gel in the trench between the lines is adhered to the wall and is not compressed by the wall and bottom of the trench. Will shrink, resulting in a high porosity substance. Then the conventional method is used to evaporate the solvent of the low volatile solvent without further shrinking and drying the film. In this step, a higher temperature can be used to dry the coating. This temperature range From 20 to about 450 ° C, preferably from about 50 ° C to about 35 ° :, and more preferably from about i7 ^ c to about 320 C. As a result, the porosity is quite high, the dielectric constant is low, The silicon polymer composition is formed between raised lines, and the polymer composition with a relatively low porosity, high dielectric constant, and crushing is formed on the line. The crushed polymer-containing composition on the top of the line preferably has a median from about 13 to about 2 · 9, preferably from about 15 to about 2.9, and most preferably from about 丨 · 8 to about 2.5 Electrical constant. The dielectric constant of the fragment-containing polymer composition between the lines is preferably at least 0.2 lower than the dielectric constant of the fragment-containing polymer composition on the top of the line. The pore size of the silica composition on the top of the line ranges from about 1 nanometer to about 100 nanometers, preferably from about 2 nanometers to about 30 nanometers, and most preferably from about 3 nanometers to about 200 nanometers. Nanometers. The density of the pores containing the silicon-containing composition on the top end of the line ranges from about 0.25 to -13.- This paper size applies to China National Standard (CNS) A4 (210 X 297 mm)

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The spoon is 19 g / cm², preferably from about 0.4 to about 1.6 g / cm², and most preferably from about 0.7 to about 1.2 g / cm². The monocoat is monolithic and has a dielectric constant gradient ranging from the upper end of the line to the lower end of the line. The difference between the average dielectric constant a at the top of the line and the average dielectric constant of the region between the lines ranges from about .2 to about 0.4, and preferably from about 0.3 to about 0.4. The average refractive index of the region between the lines "and the difference in the average refractive index of the spring-on region are in the range from about 0.04 to about 0.06 ', preferably from about 0.004 to about 0.006. Shows a relatively high density, low porosity, and high dielectric constant silica region 8 formed on the line 4 and a relatively high density, low density, and low dielectric constant silica region 1 formed on the line 4 〇. Compared with Figure 2, the area 8 on line 4 is reduced. The density difference is controlled by the degree of hydrolysis of the alkoxy group after the film is gelled. The density difference between the two layers can be determined by the number of alkane removed after the gel point And the size is fixed. As an example, the size of the alkoxy group can be borrowed by different alcohols such as methanol, ethanol, i-propanol, isopropanol or glycols such as ethylene glycol or propanol or any other can be easily approximated At room temperature, it is controlled by organic groups separated from cleavage and dreams. The number of groups can be determined by the relative concentration of the initial reaction mass of water and precursor alcohols, and the water vapor and alkali vapor applied to the film after coating. Time and temperature_concentration control. A. Suitable bases for alkaline steam include not only ammonia and For example, primary, secondary and secondary alkylamines, arylamines, alcoholamines and their boiling points are about 2000 ×: or lower, preferably 100 ° C or lower, more preferably 25 ×: Or lower. Preferred amines are methylamine, methylamine, trimethylamine, n-butylamine, n-propylamine, tetramethylammonium hydroxide, pyridine, and 2-methoxyethyl Amine. Amine accepts water

525268 A7 B7 V. Description of the invention (12) The ability of a proton can be measured by the basic constant Kb & pKb = -l0g Kb. In a preferred embodiment, the pKb of the base ranges from about below 0 to about 9. The preferred range is from about 2 to about 6 'and the most preferred range is from about 4 to about 5. In a preferred embodiment, the molar ratio of water vapor to test steam ranges from about 1: 3 to about 1: 100, preferably from about 1: 5 to about 1:50, and more preferably from about 1: 5 to about 1:50. About 1:10 to about 1:30. When coated with the test steam (catalyst) agronomy and limited water vapor, the silica polymer is polymerized and gelled with alkoxy groups retained on the inner silica surface at a significant concentration. After hydrolysis, the alkoxy group is hydrolyzed and the product alcohol is evaporated. If the gel is not compressed, it will shrink, but if it is compressed in the trench, it will not shrink and cause low density / dielectric constant. The dielectric constant (density) at the low-density slit depends on the target dielectric constant formulation, which can control the volumetric distribution of silica to the silica, the size of the alkoxy group, and the gelation of the silica polymer through the hole control The alkoxy ratio of each silicon atom is fixed at this time. This is calculated from the three common alkoxy groups (methoxy, ethoxy, and n-butoxy) and OR / Si molar ratio ranges for three different target dielectric constants and is shown below. When the 0R / S 1 Morse ratio is close to zero, as in conventional processing, there is no difference in reduction. However, when processed according to the present invention, the OR / si mole ratio of the gel point is between 0.2 and 2. For example, if mol / si molar ratio si, an ethoxy group can be used, and when the standard dry dielectric constant is 2.5, a significantly different dielectric constant will be seen. At the top, 値 (unpressed) is 2.5, and the dielectric constant 値 in the slit will be / Nai. For different alkoxy groups, as the molar volume of the alkoxy group increases (n-butoxy: ethyl lactyl group> methoxy group), the degree of differential dielectric constant increases. After gelling and final hardening (the rule of reduction is a kind of volume change caused by de-baking -15-

525268 A7 _______B7 V. Description of the invention (13) Excellent measurement method The following non-limiting examples are used to illustrate the present invention. Example 1 (comparative) This example illustrates a procedure in which a discernable differential density is seen from a thin film with an interface constant of 13 on the top layer of the target. A precursor is reacted with water and alkali before coating, which will reduce the OR: si ratio, and then coated on the patterned wafer, aged for 3 minutes, exchanged the solvent and dried it. A precursor can be synthesized by adding 61.0 ml of tetraethylsilicon, 61.0 ml of tetraethylene glycol, 4.87 ml of deionized water, and 02 ml of 1N nitric acid into a round-bottomed flask. This solution was stirred vigorously, then heated to ~ 80 and refluxed for 1.5 hours to form a solution. After allowing the solution to cool, dilute the solution with ethanol to reduce viscosity and achieve the desired thickness. The dilute precursor was filtered to 0.1 micron using a Teflon filter. Add 1 ml of OH (51) ammonium hydroxide to 10 ml of the above solution and mix for ~ 5 seconds to catalyze the precursor in advance. Approximately 3.0 milliliters of this precatalyzed precursor was coated on a 6-inch 忖 patterned wafer on a rotary table and rotated at 2500 rpm for 30 seconds to form a thin film. The film was statically aged for 10 minutes by adding 1¾ liters of 15M chloridized oxide to the bottom of a petri dish. Place the film in a Petri dish on a rack and cover the dish. Evaporate the water and ammonia produced in the petri dish and diffuse it into the film to promote gelation. This film was then solvent exchanged in a two-step procedure whereby ~ 20 ml of ethanol was rotated on the film at 250 rpm for 10 seconds without drying the film. Immediately spin the membrane at 250 rpm for nearly 20 milliliters of hexamethyldisilazine for 10 seconds. The film is heated in the air at higher temperatures of 175 ° C and 320 ° C. • 16- This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) 525268 A7 B7

1 minute. This film was cut into 1-inch squares and viewed with a scanning electron microscope (SEM). SEM photographs were taken between the pattern lines at magnifications between 100,000 and 50000 to observe the density of the entire film. No discernable density gradient was observed in the SEM photograph. Example 2 This example illustrates a procedure in which a very small differential density can be seen from a thin film with an interface constant of 13 on the top layer of the target. A precursor was coated on the patterned wafer, aged for 3 minutes, the solvents were exchanged and dried. A precursor can be synthesized by adding 61.0 ml of tetraethylsilane, 61.0 ml of tetraethylene glycol, 4.87 ml of deionized water and 0.2 ml of 1N nitric acid into a round-bottomed flask. This solution was allowed to stir vigorously, then heated to ~ 800 ° C and slurried for 1.5 hours to form a solution. After allowing the solution to cool, dilute the solution with ethanol to reduce viscosity and achieve the desired thickness. The dilute precursor was filtered to 0.1 micron using a Teflon filter. Approximately 3.0 milliliters of precursor was coated on a 6-Wu patterned wafer on a rotary table and rotated at 2500 rpm for 30 seconds. The film was statically aged for 10 minutes by adding 1 ml of 15M ammonium hydroxide to the bottom of the petri dish. Place the film in a Petri dish on a rack and cover the dish. Evaporate the water and ammonia from the culture dish and diffuse it into the film to promote aging. This film was then solvent exchanged in a two-step procedure whereby ~ 20 ml of ethanol was rotated on the film at 250 rpm for 10 seconds without drying the film. Immediately spin the film at 25 rpm for nearly 20 milliliters of hexamethyldisilazane for 10 seconds. The films were each heated in the air at higher temperatures of 175X: and 320X: for 1 minute. This film was cut into 1-inch squares and examined with a scanning electron microscope (SEM). • 17- This paper size applies to China National Standard (CNS) A4 (210 X 297 mm)

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Line 525268 A7 ------- B7 V. Description of invention (15)

SEM sheets were taken between the pattern lines at magnifications between 10,000 × and 50,000 × to observe the density of the entire film. Some micro-density gradients can be seen in the SEM photos. The material between the metal wires shows a slightly lower density than the material at the top of the wire. Example 3 Γ oblique, warm, This example illustrates a procedure in which the interface constant K is 1 · 8 < from the top layer of the target, and no discernable differential density is seen. A precursor is reacted with water and alkali before coating, which will reduce the OR: si ratio, and then coated on a patterned wafer for aging for 3 minutes, exchanging solvents and drying it. A precursor can be synthesized by adding 208.0 ml of tetraethylsilane, 610 ml of tetraethylene glycol, 16.8 ml of deionized water, and 0.67 ml of 1N nitric acid together to a round-bottomed flask. This solution was allowed to stir vigorously, then heated to ~ 80 and refluxed for 1.5 hours to form a solution. After allowing the solution to cool, dilute the solution with ethanol to reduce viscosity and achieve the desired thickness. The dilute precursor was filtered to 0.1 micron using a Teflon filter. Add the pre-catalyst of this precursor by adding 5 ml of 0. 5M ammonium hydroxide to 10 ml of the above solution and mixing for ~ 5 seconds. Approximately 3.0 milliliters of this precatalyzed precursor was coated on a 6-inch patterned wafer on a rotating table and rotated at 2500 rpm for 30 seconds. The film was statically aged for 10 minutes by adding 1 * L of 15M ammonium hydroxide to the bottom of a petri dish. Place the film in a Petri dish on a rack and cap the union. Evaporate the water and ammonia from the petri dish and diffuse them into the film to promote aging. The film was then solvent exchanged in a two-step procedure whereby ~ 20 ml of ethanol was rotated on the film at 250 rpm for 10 seconds without drying the film. Immediately spin the film at 25 rpm for nearly 20 milliliters of hexamethyldisilazane for 10 seconds. 175.0 and • 18- This paper size applies to China National Standard (CNS) A4 specifications (210X 297 mm)

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Line V. Description of the invention (The films are heated in the air at a higher temperature of 16 3 20 C each [minutes. This film is cut into 1-inch squares and viewed with a scanning electron microscope (sem). Between the pattern lines, Take a photo of the interface and Saga magnification to observe the density of the entire film. No discernable density gradient is seen in the SEM image. Example i This example illustrates a procedure where the interface constant from the top layer of the target is reversed to ^ "The claimed differential density can be seen in the film. The precursor is coated on the patterned wafer, aged for 3 minutes, the solvent is exchanged and dried .: The precursor can be obtained by using 208.0 ml of tetraethylsilane, 61. Ml of tetraethylene glycol, 16.8 ml of deionized water, and 0.67 ml of 1N nitric acid were added to the round bottom flask and synthesized. The solution was stirred vigorously, then heated to ~ 8 (rc and refluxed for 1.5 hours to A solution was formed. After the solution was allowed to cool, the solution was diluted with ethanol to reduce the viscosity and reach the desired thickness. The dilute precursor was filtered to Oj micrometers using a Teflon filter. Approximately 30 milliliters of the precursor was coated on a rotating table 6 British The wafer was patterned and rotated for 30 seconds at 25,000 rpm. The film was statically aged for 10 minutes by adding 1 ml of 15M ammonium hydroxide to the bottom of the Petri culture. The film was placed on a shelf and cultured. Replace the dish and cover the fox. Evaporate the water and ammonia from the dish and diffuse it into the film to promote aging. The film is then exchanged with a solvent in a two-step procedure, whereby ~ 20 ml of ethanol was spun on the film at 250 rpm for 10 seconds without drying the film. Immediately spin nearly 20 ml of hexamethyldisilazane on the film at 250 rpm for 10 seconds The film was heated in the air for 1 minute at the southern temperatures of 175 C and 320 C. End 525268 A7 B7 V. Description of the invention (17) Focused ion beam (FIB) analysis to reduce sample separation during sample preparation Hazards. Then inspect the film with a scanning electron microscope (SEM). Take a SEM picture between the pattern lines at a magnification between 10, 00 × and 50,000X to observe the density of the entire film. This thin surface shows the claimed density difference .Between the lines The material shows a density that is much lower than the material at the top of the line. From the above examples and disclosures, it can be seen that according to the present invention, a silicon-containing polymer composition having a low density is formed between pattern lines on a semiconductor substrate, and at the same time, the top of the line The silicon-containing polymer composition has a high density. -20- This paper size applies to China National Standard (CNS) A4 (210X 297 mm)

Claims (1)

525268 Patent Application No. 090127661 Chinese Patent Application Replacement (January 1992) A8 B8 C8 D8 6. Scope of Patent Application 1. A multi-density nano-level microporous dielectric coated substrate, comprising a substrate, a plurality of raised lines on the substrate, and a single monolithic nano-scale micro-pore-containing polymer combination A layer on the substrate, wherein the layer includes a first region composed of a graded density, high porosity, low dielectric constant, nano-scale microporous silicon-containing polymer composition located between raised lines, and The top of the line is a second region composed of a graded density, low porosity, high dielectric constant, nano-scale microporous silicon-containing polymer composition, wherein the average refractive index of the second region and the average refractive index of the first region The difference between the rates ranges from about 0.03 to about 0.06. 2. The multi-density nanoscale microporous dielectric coated substrate according to item 1 of the patent application range, wherein the difference between the average refractive index of the second region and the average refractive index of the first region is from about 0.04 to In the range of about 0.06. 3. The multi-density nanoscale microporous dielectric coated substrate according to item 1 of the scope of patent application, wherein the difference between the average dielectric constant of the second region and the average dielectric constant of the first region is from about Within the range of 0.2 to about 0.4. 4. The multi-density nanoscale microporous dielectric coated substrate according to item 1 of the patent application, wherein the difference between the average dielectric constant of the second region and the average dielectric constant of the first region is from about 0.3 to about 0.4. 5. The multi-density nano-scale microporous dielectric coated substrate according to item 1 of the patent application scope, wherein the high porosity, low dielectric constant, silicon-containing composition has a dielectric from about 1.1 to about 2.5 constant. 6. The multi-density nano-scale microporous dielectric coated substrate according to item 1 of the patent application scope, wherein the low porosity, high dielectric constant, silicon-containing composition has a dielectric from about 1.3 to about 2.9 constant. This paper size applies to China National Standard (CNS) A4 specification (210 X 297 mm) 々, patent application scope 7. Multi-density nano-level microporous dielectric coated substrates according to item η of the patent application scope, where The high porosity, low dielectric constant, silicon-containing composition has a dielectric constant that is at least lower than the low porosity, high dielectric constant, silicon-containing composition by about 0.2. 8. The multi-density nano-scale microporous dielectric coated substrate according to item 1 of the patent application scope, wherein the protruding pattern line comprises a metal, an oxide, a nitride, and / or an oxynitride material. 9. A multi-density nanoscale microporous dielectric coated substrate according to item 1 of the patent application, wherein the substrate comprises a semiconductor material. 10. A multi-density nanoscale microporous dielectric coated substrate according to item 1 of the scope of the patent application, wherein the substrate comprises silicon or gallium arsenide. 11. A semiconductor device including a base plate, wherein the base plate includes a substrate, a plurality of raised lines on the substrate, and a single monolithic nano-scale microporous silicon-containing polymer composition layer on the substrate, wherein the layer includes The first region is composed of a graded density, high porosity, low dielectric constant, nano-scale microporous silicon-containing polymer composition, and a graded density, low porosity is located on the top of the line. , A high dielectric constant, nano-sized microporous silicon-containing polymer composition, wherein the difference between the average refractive index of the second region and the average refractive index of the first region is from about 0.03 to about Within 0.06. 12. A method of forming a multi-density nanoscale microporous dielectric coating on a substrate having raised pattern lines, comprising-a) combining at least one alkoxysilane with a highly volatile solvent composition, Solvent composition with relatively low volatility and water as appropriate -2- This paper size applies to Chinese National Standard (CNS) A4 specification (210X 297 mm) ABC D 525268 Six, patent application blending, so a mixture is formed And cause partial hydrolysis and partial condensation of the alkoxysilane; b) the mixture is coated on a substrate with raised pattern lines, the mixture is placed between the lines and the line, and at least a part of the volatility is distilled off Quite high solvent composition; C) exposing the mixture to water vapor and alkali vapor; and d) evaporating off the solvent composition with relatively low volatility, thus forming a single monolithic nanoscale microporous silicon-containing polymer The composition layer is on the substrate, and the layer includes a first region composed of a graded density, high porosity, low dielectric constant, nano-scale microporous silicon-containing polymer composition located between the raised lines, and A second region composed of a graded density, low porosity, high dielectric constant, nano-scale microporous silicon-containing polymer composition on the top of the line, wherein the average refractive index of the second region is the same as that of the first region. The difference between the average refractive indices is in a range from about 0.03 to about 0.06. 13. The method according to item 12 of the patent application range, wherein the difference between the average refractive index of the second region and the average refractive index of the first region is in a range from about 0.04 to about 0.06. 14. The method according to item 12 of the patent application range, wherein the difference between the average dielectric constant of the second region and the average dielectric constant of the first region is in a range from about 0.2 to about 0.4. 15. The method according to item 12 of the scope of patent application, wherein the difference between the average dielectric constant of the second region and the average dielectric constant of the first region is in a range from about 0.3 to about 0.4. -3- This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) J〇268 AS B8 --CS… " --- • According to the method of item 12 in the scope of patent application, where The high porosity, low 171 coefficient, silicon-containing composition has a dielectric constant from about 1.1 to about 2.5. = The method according to item 12 of the patent application range, wherein the low porosity, high %%, silicon-containing composition has a dielectric constant from about 1.3 to about 2.9. = The method according to item 12 of the scope of patent application, wherein the high porosity, a low number of two, the silicon-containing composition has at least less than the low porosity, a high dielectric constant, and the silicon-containing composition is about 0.2 Dielectric constant. 19. The method of claim 12 in which the protruding pattern line includes a metal, an oxide, a nitride, and / or an oxynitride material. 20. The method according to item 12 of the patent application, wherein the substrate comprises a plurality of semiconductor materials. 21. The method according to item 12 of the application, wherein the substrate comprises silicon or gallium. -4-This paper size applies to China National Standard (CNS) A4 (210 X 297 mm)