TWI423306B - Adaptive nanotopography sculpting - Google Patents

Description

Adaptive nanotopography etching Cross-references for related applications

This application claims the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit of the benefit.

The present invention relates to adaptive nanotopography etching techniques.

Background information

Nanofabrication includes the fabrication of very minute constructions, such as surface features having a rating of 100 nanometers or less. One area of application in which nanofabrication produces considerable impact is the processing of integrated circuits. Nanofabrication has thus become more important as the semiconductor processing industry continues to focus on greater yields while increasing the number of circuits per unit area formed on the substrate. Nanofabrication provides better process control while reducing the size of the smallest features that form the structure. Other emerging areas of manufacturing using nanotechnology include biotechnology, optical technology, mechanical systems, and the like.

The instant nanofabrication technique used today is commonly referred to as imprint lithography. The exemplified embossing lithography process is described in detail in several publications, such as U.S. Patent Publication No. 2004/0065976, U.S. Patent Publication No. 2004/0065252, and U.S. Patent No. 6,936,194, the entire contents of which are incorporated herein by reference. This is incorporated herein by reference.

The embossing lithography techniques disclosed in each of the above-mentioned U.S. Patent Publications and Patents include forming a relief pattern in a formable layer (polymerizable) and converting a pattern of the corresponding relief pattern into the underlying substrate. The substrate can be coupled to a moving stage to achieve the desired positioning to facilitate the patterning process. The patterning process uses a template that is spatially separated from the substrate and applies a formable liquid between the template and the substrate. The formable liquid is cured to form a patterned hard layer that conforms to the shape of the surface of the template that contacts the formable liquid. After curing, the template is separated from the hard layer to spatially separate the template from the substrate. The substrate and hard layer are then subjected to additional processing to convert the relief image into the substrate corresponding to the pattern in the hard layer.

Processing techniques using embossing lithography rely on the presence of a substrate below the substantially planar plane or a layer below the substantially planar plane. For example, during fabrication of a layer-stacked semiconductor device, the reliability and ease of fabrication depend on the topography of the substantially planar substrate.

In the context of semiconductor fabrication, the term "planarization" is used broadly to describe two processes: wafer surface topography improvement after material deposition process (eg, planarization of interlayer dielectric (ILD)); or removal The film is deposited to provide material within the recessed regions (eg, shallow trench isolation (STI), damascene processes, etc.).

Various planarization methods have been developed including thermal and reflow techniques, glass on-glass (SOG) processes, and the like. However, the degree of planarity obtained by current methods may be limited. For example, one of the commonly used planarization techniques, chemical mechanical manufacturing (CMP), typically relies on material removal rates based on material pattern density. A zone of high pattern density has more contact area than a zone of lower pattern density. This can result in more pressure being applied in the low pattern density zone, thus resulting in a higher material removal rate in the low density zone. The low density zone is first planarized, and then the localization is achieved in the high density zone after the material is removed at a fixed rate. This creates a step-like structure between the high density and low density zones and provides a long range of thickness variations within the planarization film. Prevention techniques, such as imitation fill and pattern impedance, are used to reduce variations in pattern density. However, these techniques increase the complexity of the planarization process.

A contact planarization that can replace CMP provides a substrate that is spin coated with a photocurable material and pre-baked to remove residual solvent. The ultra-flat surface can be pressed onto the spin-coated wafer to force the material back down, and pressure can be used to evenly distribute the material to achieve planarization. However, the quality of the flattening is offset by the change in pattern density. Spin coating is generally believed to provide a uniform fluid distribution on the substrate. As such, regions with varying density will generally have the same fluid distribution. When the material is pressed against an ultra-flat surface, the material readily flows from a high surface feature density zone to a low surface density zone. The high viscosity of the material and/or material mobility from the ultra-flat surface and the rills formed between the substrates may limit backflow. In addition, the fluid force between the ultra-flat surface and the substrate can cause tensile stresses within the fluid film. When the ultra-flat surface is removed, this stress is released and thus causes surface planarity damage.

Moreover, CPs generally do not cause large variations in surface feature density. For example, if a bottom mold having a low pattern density has a large strip, the material cannot be reflowed to fill the void, and thus may affect the spherical planarity. In addition, CPs generally cannot explain the difference in surface topography of substrates and/or ultra-flat surfaces. For example, when an ultra-flat surface is pressed against a substrate, the thickness of the material between them may vary. The use of a very thick film of material improves the fluidity of the fluid, however, it is difficult to transfer the same planarity to the substrate because the inconsistency of subsequent material removal processes (eg etching, polishing, etc.) is thicker The film will be very noticeable.

In accordance with an embodiment of the present invention, a method of forming a surface having a desired shape characteristic using an embossing lithography system is specifically provided, comprising: determining a nanotopography of a first surface; determining a second surface Desiring a shape characteristic; evaluating a nanotopography of the first surface and a desired shape characteristic of the second surface to provide a droplet pattern; placing the polymerizable material on the same plate and the first surface according to the droplet pattern Contacting the template with the polymerizable material; curing the polymerizable material; etching the polymerizable material to provide a second surface having the desired shape characteristics.

In accordance with another embodiment of the present invention, a method of forming a surface having a desired nanotopography using an embossing lithography system is specifically provided, comprising: determining a nanotopography of a surface; evaluating the surface of the nanometer The topography determines the height of the nanotopography of the surface compared to a desired nanotopography; the nanotopography based on the surface is compared to the desired nanotopography Height correction provides a density map; determining a droplet pattern based on the density map; placing a polymerizable material between the imprint lithography template and the surface according to the droplet pattern; contacting the template with the polymerizable material; curing The polymerizable material; the polymerizable material is etched to provide a surface having the desired nanotopography.

According to still another embodiment of the present invention, a method for forming a planar surface using an embossing lithography system is specifically provided, comprising: determining a nanotopography of a surface; and evaluating a nanotopography of the surface to determine a droplet Patterning to provide the planar surface for a first polymerizable material having a first etch rate and a second polymerizable material having a second etch rate; placing the first polymerizable material and the second according to the droplet pattern The polymerizable material is between an imprint lithography template and the surface; contacting the template with at least one of the first polymerizable material and the second polymerizable material; curing the first polymerizable material and the second At least one of the polymerizable materials; etching at least one of the first polymerizable material and the second polymerizable material to provide the planar surface.

Simple illustration

In order to understand the present invention in detail, the description of the embodiments of the invention is provided by reference to the accompanying drawings. It is to be understood, however, that the appended claims

1 shows a simplified side view of an imprint lithography system in accordance with an embodiment of the present invention.

Figure 2 shows a simplified side view of the substrate with the patterned layer placed therebetween as shown in Figure 1.

Figure 3 shows a simplified side view of the topographical changes of most of the layers due to the underlying substrate.

Figures 4A and 4B each show a simplified side view of the planarity variation of the local topography and the planarity variation of the spherical morphology.

5A-5D show a simplified side view of a surface having the desired shape characteristics using an adaptive nanotopography etch technique.

Figure 6 shows a flow diagram of one embodiment of a method of forming a surface having a desired shape characteristic using an adaptive nanotopography etching technique.

Figure 7 shows a flow diagram of one embodiment of a mapping process that provides a droplet pattern for one of the adaptive nanotopography etching techniques.

Figure 8 shows a flow diagram of one embodiment of a method for pre-polishing a substrate surface.

Figure 9 shows a simplified side view of a surface having non-flat, desired shape characteristics.

Figures 10A-10C show simplified side views of the surface forming features having non-flat, desired shapes.

Detailed description

Referring to the drawings, and in particular, FIG. 1, a lithography system 10 for forming a relief pattern on a substrate 12 is shown. Substrate 12 can be coupled to substrate chuck 14. As shown, the substrate chuck 14 is a vacuum chuck, however, the substrate chuck 14 can be any chuck including, but not limited to, vacuum, needle, groove, electrostatic or electromagnetic chucks and/or Analogs, exemplified chucks are described in U.S. Patent No. 6,873,087, incorporated herein by reference.

The substrate 12 and the substrate holder 14 can be supported on the stage 16. Stage 16 can provide movement about the x, y, and z axes. The stage 16, substrate 12 and substrate chuck 14 can be positioned on a substrate (not shown).

The substrate 12 is spatially separated from the template 18. The template 18 can include a mesa 20 extending from the template 18 toward the substrate 12 having a patterned surface 22 thereon. Moreover, the table top 20 can be referred to as a module 20. Alternatively, the template 18 may not require the countertop 20.

The template 18 and/or the mold 20 may be formed from materials including, but not limited to, fused vermiculite, quartz, ruthenium, organic polymers, siloxane polymers, borosilicate glass, fluorocarbon polymers, metals, Hardened sapphire and/or the like. As shown, although the patterned surface 22 includes surface features defined by a plurality of spatially separated recesses 24 and protrusions 26, embodiments of the invention are not limited to such configurations. The patterned surface 22 can define any original pattern that forms the basis of the pattern to be formed on the substrate 12.

The template 18 can be coupled to the collet 28. The collet 28 can be configured, but not limited to, a vacuum, a needle, a groove, an electrostatic or electromagnetic, and/or the like. The exemplified collet is further described in U.S. Patent No. 6,873,087, incorporated herein by reference. Moreover, the collet 28 can be coupled to the imprint head 30 such that the collet 28 and/or the imprint head 30 can be configured to facilitate movement of the template 18.

System 10 can further include a fluid dispensing system 32. Fluid dispensing system 32 can be used to deposit polymerizable material 34 onto substrate 12. The polymerizable material 34 can be placed using techniques such as droplet dispensing, spin coating, dip coating, chemical vapor deposition (CVD), physical vapor deposition (PVD), thin film deposition, thick film deposition, and/or the like. On the substrate 12. Depending on design considerations, the polymerizable material 34 can be deposited on the substrate 12 before or after the desired volume is defined between the mold 20 and the substrate 12. The polymerizable material 34 can include a mixture of monomers, as described in U.S. Patent No. 7,157,036, and U.S. Patent Publication No. 2005/0187339, the entire disclosure of which is incorporated herein by reference.

Referring to Figures 1 and 2, system 10 further includes an energy source 38 coupled to direct energy 40 along path 42. The embossing head 30 and the stage 16 are configured to place the template 18 and the substrate 12 in a position overlapping the path 42. The system 10 can be regulated by the processor 54 to communicate with the stage 16, the imprint head 30, the fluid dispensing system 32, and/or the source 38, and operates in accordance with a computer readable program stored in the memory 56.

Either or both of the embossing head 30 or stage 16 can vary the distance between the module 20 and the substrate 12 to define a desired volume therebetween that can be filled with the polymerizable material 34. For example, the imprint head 30 can be forced to the template 18 such that the module 20 contacts the polymerizable material 34. After the desired volume is filled with the polymerizable material 34, the source 38 produces energy 40, such as broadband ultraviolet radiation, such that the polymerizable material 34 cures and/or crosslinks to conform to the shape of the surface 44 of the substrate 12 and pattern the surface 22, And defining a patterned layer 46 on the substrate 12. Pattern layer 46 includes a residual layer 48 and a plurality of surface features such as protrusions 50 of the recess 52 as shown, and the projections 50 having a thickness t ₁ and residual layer having a thickness t _2.

The above system and process can be further used in U.S. Patent No. 6,932,934, U.S. Patent Publication No. 2004/0124566, U.S. Patent Publication No. 2004/0188381, and U.S. Patent Publication No. 2004/0211754 The imprint lithography process and system described in the reference).

Referring to FIG. 3, the material deposition process generally provides a film layer 60 of material that maintains the same topography as the underlying substrate 62. As the number of layers 60 increases, the step height hF of the surface features 64 increases to the resulting step height hR1 and then further increases to the resulting step height hR2, as shown in FIG. This increase can lead to changes in topography.

Large changes in topography can hinder the manufacturing process and/or cause reliability problems. For example, in semiconductor processing, in order to minimize large topographical variations, the wafer is polished to improve surface planarity. Roughness, site front secondary surface topography and spherical backplane indication range (GBIR) are used to quantify the measurement of surface topography in low, medium and large spatial wavelengths. A typical 300 mm top-level wafer for 90 nm intersection fabrication has a roughness of less than 1 nm, an SFQR of approximately 90 nm, and a GBIR of 2 microns. In comparison, the 75 mm top wafer has a roughness of less than 5 nm, an SFQR of 1000 nm, and a GBIR of 10 microns. However, in order to meet stringent planarity requirements, the wafer will undergo several polishing steps, which typically adds cost. In addition, small-sized wafers, as well as other material wafers, often fail to meet stringent planarity requirements and are therefore often not available for fabrication of devices with submicron surface features.

Figures 4A and 4B show local topographical planarity variations 66 and spherical topographical variations 68, such as those seen during semiconductor fabrication. When the deposited material conforms to the underlying surface features that reflect the change in the underlying surface, a local topographical variability 66 is produced. These variations 66 may have the same scale level (e.g., surface feature height) and/or may have low spatial wavelengths.

As shown in FIG. 4B, the spherical topography variation 68 can be a larger scale and a spatial wavelength having a bottom size rating. A spheroidal planarity variation 68 can be observed above the zone where the pattern density is significantly changed. While the 26x33mm sized patterning field allows the entire field to be simultaneously exposed for patterning, there are large topographical variations due to the overall wafer surface topography (eg, thickness variations), as opposed to the target pattern. This large topographical change can be graded at the wafer diameter.

When analyzed in the spatial wavelength domain, the height variation of the surface can be classified into three components: the nominal shape (height change in spatial wavelength > 20 mm), and the nanomorphology (the variation in spatial wavelength is 0.2-20) Between mm) and surface roughness (height change in spatial wavelength <0.2 mm). Adaptive nanotopography etching techniques, as described herein, can be used to alter the nanotopography. In addition, adaptive nanotopography etching techniques, as described herein, can be used to alter the roughness. For example, adaptive nanotopography etch techniques can alter the surface roughness of substrates (eg, bare enamel wafers), sub-micron surface feature substrates, and the like. It should be noted that adaptive nanotopography etching techniques can be used to alter the nanotopography and/or roughness without altering the nominal shape of the surface.

Referring to Figures 5A-5D, the adaptive nanotopography etch technique can be used in nanoetching techniques and adaptively minimizes nanomorphology variations such as local and/or spheroidal planarity variations. The nanoetching technique begins with the first surface 74 and provides a second surface 76 of the desired surface topography (e.g., planar) by deposition and etching back to a suitable depth.

With the lithography system 10 illustrated in FIG. 1 and described herein, the adaptive nanotopography etch process can be adapted to the pattern density on the varying surface 74. Referring to FIG. 5B, polymerizable material 34 may be deposited on the film layer 60a (e.g. SiO ₂₎ 74 on the first surface. The polymerizable material 34 can be positioned on the first surface 74 using the droplet disperser described herein such that various numbers of polymerizable materials 34 can be positioned at specific locations on the first surface 74.

Typically, the distance between the template 18 and the first surface 74 is varied to define the desired volume filled by the polymerizable material 34 therebetween. The template 18 can include a module 20 having a substantially flat patterned surface 22. Applying to the template 18 causes the template 18 to contact the polymerizable material 34, causing the polymerizable material 34 to form a substantially connected film and substantially fill the desired volume. Further, a capillary force can be utilized to disperse the polymerizable material 34 to form a film. After the desired volume is filled with the polymerizable material 34, the polymerizable material 34 can be cured to define a patterned layer 46a comprising a surface 78, defined by a thickness t3. A removal process (e.g., etching, polishing, CMP, etc.) is then used to transfer the surface of the pattern layer 46 to provide a second surface 76 having the desired surface topography.

Deposition of a material (e.g., polymerizable material 34) onto the first surface 74 can achieve a desired surface topography of the second surface 76. In addition, the deposition of materials can compensate for parasitic effects in various processes (such as reducing the effects of desired surface topography, including but not limited to, pattern density changes, long-range crystal domes, inconsistent etching, inconsistent polishing, CMP inconsistency Inconsistent material removal rate, volume reduction, evaporation, etc.).

Typically, the deposition disperses the polymerizable material 34 to provide a sufficient volume over selected areas on the first surface 74 such that during removal (e.g., etching), the desired surface topography of the second surface 76 can be provided. Accordingly, the deposition can be adapted to vary the pattern density on the first surface 74, the underlying layer, and/or the like to provide the desired shape characteristics (e.g., substantially similar topography, planarity, odd shape of the surface 72 of the substrate 62a). And/or other desired shape characteristics of the second surface 76. Based on the topography of the first surface 74, deposition typically disperses the polymerizable material 34, as further provided herein. For example, the polymerizable material 34 that increases the droplet volume or increases the number of droplets can be dispersed at a low density of the first surface 74 to compensate for pattern density variations. This pattern density variation results from a change in the pattern density of the underlying layer 62a and/or surface features 64a.

Referring to Figure 6, an adaptive nanotopography etch technique can utilize (a) a top surface 74 topography, (b) provide parameters required for the second surface 76, and (c) spatial distribution parameters to provide for A dispersion pattern of the polymerizable material 34 on the first surface 74 is deposited. In step 100, a starting topography map 80 of the first surface 74 is provided. In step 102, it is decided to provide parameters (e.g., planarized length, thickness, desired final topography) of the second surface 76 having the desired surface topography. In step 104, a droplet pattern 86 of polymerizable material 34 is provided based on the starting topography map 80 and the second surface 76 parameters. In step 106, small droplets of polymerizable material 34 are dispersed based on droplet pattern 86. In step 108, the template 18 contacts the polymerizable material 34. In step 110, the polymerizable material 34 is cured to form the patterned layer 46a. In step 112, a portion of the pattern layer 46a is removed to provide a second surface 76 having a desired surface topography.

Referring to Figure 7, a surface scanning system can provide a topographic map 80. For example, the Zygo ^viii surface scanning system can be used with a 250 x 250 μm sampling barrier. The difference between the topographical map 80 provided to the first surface 74 and the desired topography of the second surface 76 can provide a height correction for the position provided by each of the correction maps 82. This information is further converted to provide a surface feature density map 84. The surface feature density map 84 can provide the density of the polymerizable material 34 necessary to cause the various locations of the drop pattern 86.

Referring to Figures 5A-5D, several parameters may be determined and/or balanced to provide control over the spatial distribution of the polymerizable material 34, including but not limited to the thickness t3 of the pattern layer 46a, the viscosity of the polymerizable material 34, The time interval between the polymeric material 34 being dispersed and exposing the polymerizable material 34 to energy, the stiffness of the template 18, and/or similar parameters.

The spatial distribution of the polymerizable material 34 can be correlated to the spatial distribution of the volume of the dispersed polymerizable material 34. For example, the polymerizable material 34 can be dispersed in a droplet form to provide a joined film, while substantially remaining where the droplets of the polymerizable material 34 are dispersed (e.g., to minimize lateral movement on the surface 74). This correction can be achieved to provide a thickness t3 of about 20 nm to 250 nm. Moreover, the viscosity of the polymerizable material 34 (e.g., 3 centipoise to 100 centipoise) provides resistance to the free lateral flow of the polymerizable material 34.

The spatial distribution is also associated with the time interval between exposure of the polymerizable material 34 and the polymerizable material 34 to exposure to energy (eg, UV exposure). For example, a sufficient time for the polymerizable material 34 to be dispersed and the polymerizable material 34 to be exposed to energy may be sufficiently long to allow droplets of the polymerizable material 34 to form a connected film, but is sufficiently short that the lateral fluid flow is significant reduce. A sufficient time interval can range from a few seconds to a few minutes.

The hardness (e.g., thickness and/or material properties) of the template 18 is also associated with the spatial distribution of the polymerizable material 34. For example, the hardness should be sufficiently high to minimize deformation of the individual droplets of polymerizable material 34 to provide for the formation of a joined film, but should be sufficiently low to quickly conform to the distribution of polymerizable material 34 and surface 74 of film layer 60a. Low spatial frequency shape. A suitable hardness is between 0.25 mm and 2 mm.

Adaptive nanotopography etching techniques can also compensate for various parasitic effects 112. Parasitic effects can affect the shape of the resulting second surface 76 and can include, but are not limited to, pattern density variations, long range crystal domes, etch inconsistencies, polishing inconsistencies, material removal rates, volume reduction, evaporation, and the like. For example, the droplet pattern 86 (as shown in FIG. 7) can be determined by varying the volume of the polymerizable material 34 across the first surface 74 to compensate for pattern density variations. The change in volume of the polymerizable material 34 can be based on pre-existing pattern density variations and/or predicted pattern density changes.

Additionally, the volume of polymerizable material 34 dispersed on the first surface 74 can be determined to provide the patterned layer 46a of the desired shape. Adjusting the volume to provide the desired shape of the pattern layer 46a may further provide a nanoetching technique for the surface topography of the second surface 76.

The adaptive nanotopography etch technique also compensates for the inconsistency of the parasitic effects of the etch. Generally, the polymerizable material 34 can be removed at the same rate as the desired shape of the material forming the second surface 76. However, these processes have inconsistent removal rates based on the characteristics of the particular removal process and/or equipment (ie, etch characterization). Inconsistent removal can cause damage to the desired shape characteristics (e.g., surface planarity) of the second surface 76. Etching characterization of particular processes and/or equipment can be determined by several experiments. Once the etch characterization is determined, the volume of polymerizable material 34 can be adjusted based on the etch characterization. For example, the drop pattern 86 (as shown in FIG. 7) is adjusted based on the etch characterization to compensate for the zone having a relatively high etch rate.

The volume reduction of the polymerizable material 34 can also be compensated for using an adaptive nanotopography etch technique to provide a second surface 76 having desirable characteristics (e.g., planarity). As detailed above, the polymerizable material 34 cures when exposed to energy. This curing process is accompanied by a reduction in the volume of the polymerizable material 34. For example, depending on the composition of the polymerizable material 34, the reduction can be from about 5-25%. The reduction will vary depending on the local volume that can vary above the first surface 74, and will create stress within the film of the cured polymerizable material 34. This reduction effect can be compensated for by varying the distribution of the polymerizable material 34 within the droplet pattern 86. Additionally or alternatively, the removal and/or deformation stress by the template 18 can be removed.

Evaporation is another parasitic effect that can be compensated for by the use of adaptive nanotopography etching techniques. The evaporation rate of the polymerizable material 34 can be high depending on the composition. For example, leakage of the polymerizable material 34 may result due to subsequent evaporation of the polymerizable material 34 after deposition but prior to imprinting. Near the edge of the first surface 74, evaporation is generally higher.

The volumetric leakage expected in the droplet pattern 86 due to evaporation can also be determined and compensated to provide a second surface 76 having desired characteristics (e.g., planarity). For example, airflow maintained to control humidity, temperature, particle agglomeration, and the like can cause inconsistent evaporation. This airflow can cause systematic inconsistent evaporation. The evaporation profile can be determined and compensated for by adjusting the droplet pattern 86 to provide a second surface 76 having desired shape characteristics (e.g., planarity).

The adaptive nanotopography etch technique also compensates for variations in the polymerizable material 34. For example, the first polymerizable material and the second polymerizable material can be dispersed on the first surface 74, and the first polymerizable material is different from the second polymerizable material. The removal rate (e.g., etch rate) of the first polymerizable material can be different than the second polymerizable material. Accordingly, the droplet pattern 86 can be adjusted to provide a first volume of the first polymerizable material to be dispersed and a second volume to which the second polymerizable material is to be dispersed to minimize the effects of different removal rates.

Adaptive nanotopography etching techniques can be employed to replace physical polishing applications such as substrate polishing, polishing of pre-patterned substrates, polishing of non-planar surfaces, and application of non-planar nanotopography with other The process of description. For example, an adaptive nanotopography etch technique can be used to replace substrate polishing, such as, for example, planarization of a nominal surface of a bare ruthenium substrate. In the removal step, the material to be etched using the adaptive nanotopography etching technique may be a large substrate material including, but not limited to, germanium, SiO ₂ , GaAs, InP, sapphire, and/or the like.

Figure 8 shows a method 120 of using an adaptive nanotopography etch technique to replace the polishing of a pre-patterned substrate, such as, for example, in a patterned layer application to provide a planarized surface. Typically, based on the pattern sketch, the drop pattern 86 is adjusted to create an additional offset of the pattern surface features. For example, dispersing the polymerizable material 34 on the first surface 74 can include a volume change of a pre-existing pattern.

In step 122, the nanotopography of the surface can be mapped. For example, the nanotopography of the first surface 74 can be mapped using a Zygo instrument, a profilometer, or the like. In step 124, a difference between the first surface 74 and the desired final nanotopography (e.g., second surface 76) may be determined to provide a droplet pattern 86. In step 126, a parasitic effect can be determined to adjust the drop pattern 86. In step 128, a droplet pattern 86 can be used to place the polymerizable material 34 on the first surface 74 to provide a second surface 76 having the desired shape characteristics. In step 130, a template 17 can be placed to contact the polymerizable material 34. In step 132, the polymerizable material 34 can be cured using an imprint lithography template 18. In step 134, the cured polymerizable material can be etched to provide a second surface 76 having the desired shape characteristics.

The second surface 761 is etched back (etch back) to the shape of the step is transferred to the desired properties is formed: the application of the patterned substrate in a pattern in the etchable material 1 may be provided (e.g. ₂ SiO) appears in. If the pattern appears in a material that cannot be etched immediately (such as copper), the adaptive nanotopography etch technique can be used in conjunction with another material removal method (such as chemical mechanical polishing) in addition to or instead of etching. The desired shape characteristics of the second surface 76 are provided.

Referring to Figure 9, an adaptive nanotopography etch technique can be used to produce non-flat, desired shape characteristics with respect to the second surface 76. For example, the second surface 76 can have a concave shape, a convex shape, a spherical shape, an aspherical shape, a continuous periodic shape, or any other unusual shape. In general, additional changes (e.g., adjustments to the calculations) on the decision droplet pattern 86 (as shown in Figure 7) may provide a change in the second surface 76. For example, the second surface 76 shown in FIG. 9 may have a spherical convex shape with a large radius of curvature, where h may range from 10 nm to 10 microns and w may range from 1 mm to 1000 mm.

The adaptive nanotopography etch technique can also handle the problem of the nanotopography of any freeform surface (i.e., non-planar surface). For example, a nominal shape (i.e., a change in height with a spatial wavelength > 20 mm) can be affected by a number of manufacturing processes (e.g., casting, machining, grinding, and the like), but is generally unaffected during polishing. The polishing process has the ability to match the nominal shape. Conventional polishing processes generally do not affect the nominal shape, but changes in pattern density can affect the nanotopography. Moreover, conventional polishing tools require significant changes in mechanical design to accommodate changes in the nominal shape of the substrate (eg, mechanical designs for flat surface CMP may be very different from mechanical designs for spherical surface CMP). Accordingly, conventional polishing tools only deal with the problem of spherical/aspheric/symmetric shapes. However, the adaptive nanotopography etch technique can address the problem of nanotopography variations of freeform surfaces such as, for example, the freeform surface (e.g., first surface 74) shown in Figures 10A-10C. As shown in these figures, an embossed lithography template 18a having a shape complementary to the freely formed first surface 74 can also be used to provide a nanotopography of the second surface 76 as compared to the first surface 74. The change.

In the adaptive nanotopography etching technique of a spherical/aspheric lens, these pairs of lenses can be mechanically thinned. For example, these pairs of lenses can be mechanically thinned to a thickness of about 500 microns. This spherical and/or flexible piece of material can be used as a template 18a for embossing lithography. For other freeform shapes, PDMS templates can be made using castings of the desired complementary shape.

In addition to this, or instead of a complementary shaped template 18a (e.g., template 18), a pressurized recessed collet can be used to control the radius of the nominal shape of the template 18a. For example, this process can be used when polishing a spherical/aspherical surface having a specific nominal shape defined by the collet design and/or the geometry of the template 18a.

Alternatively, the template 18a can be designed to have a minimum thickness made from a non-fragile material. The template 18 can be arbitrarily bonded to a thicker fused stone frame to provide additional strength. Typically, the fused stone frame provides an adapter role between the collet and the template 18.

10. . . system

12. . . Substrate

14. . . Substrate chuck

16. . . Stage

18. . . Template

18a. . . Template

32. . . Fluid distribution system

34. . . Polymerizable material

38. . . Energy source

40. . . energy

42. . . path

44. . . Substrate surface

20. . . Countertop/module

twenty two. . . Patterned surface

twenty four. . . Recess

26. . . Protrusion

28. . . Sample chuck

30. . . Imprint head

46. . . Pattern layer

46a. . . Pattern layer

48. . . Residual layer

50. . . Protrusion

52. . . Recess

54. . . processor

56. . . Memory

60a. . . Film layer

62. . . Substrate

62a. . . Substrate

64. . . Surface feature

64a. . . Surface feature

66. . . Local topography

68. . . Spherical morphology

72. . . surface

74. . . First surface

76. . . Second surface

80. . . Start shape map

82. . . Correction map

84. . . Surface feature density map

86. . . Droplet pattern

100,102,104,106. . . step

108,110,112. . . step

120. . . method

122,124,126,128. . . step

130,132,134. . . step

1 shows a simplified side view of an imprint lithography system in accordance with an embodiment of the present invention.

Figure 2 shows a simplified side view of the substrate with the patterned layer placed therebetween as shown in Figure 1.

Figure 3 shows a simplified side view of the topographical changes of most of the layers due to the underlying substrate.

Figures 4A and 4B each show a simplified side view of the planarity variation of the local topography and the planarity variation of the spherical morphology.

5A-5D show a simplified side view of a surface having the desired shape characteristics using an adaptive nanotopography etch technique.

Figure 6 shows a flow diagram of one embodiment of a method of forming a surface having a desired shape characteristic using an adaptive nanotopography etching technique.

Figure 7 shows a flow diagram of one embodiment of a mapping process that provides a droplet pattern for one of the adaptive nanotopography etching techniques.

Figure 8 shows a flow diagram of one embodiment of a method for pre-polishing a substrate surface.

Figure 9 shows a simplified side view of a surface having non-flat, desired shape characteristics.

Figures 10A-10C show simplified side views of the surface forming features having non-flat, desired shapes.

10. . . system

12. . . Substrate

14. . . Substrate chuck

16. . . Stage

18. . . Template

20. . . Countertop/module

twenty two. . . surface

twenty four. . . Recess

26. . . Protrusion

28. . . Chuck

30. . . Imprint head

32. . . Fluid distribution system

34. . . Polymerizable material

38. . . Energy source

40. . . energy

42. . . path

44. . . surface

54. . . processor

56. . . Memory

Claims (20)

A method of forming a surface having a desired shape characteristic using an embossing lithography system, comprising: determining a nanotopography of a first surface; determining a desired shape characteristic of a second surface; evaluating the The nanotopography of the first surface and the desired shape characteristic of the second surface to provide a droplet pattern; the polymerizable material is placed between the same panel and the first surface in accordance with the droplet pattern; A template contacts the polymerizable material; the polymerizable material is cured; the polymerizable material is etched to provide the second surface having the desired shape characteristics. The method of claim 1, further comprising determining at least one parasitic effect and adjusting the droplet pattern to compensate for the parasitic effect. The method of claim 2, wherein the parasitic effect is evaporation of the polymerizable material. The method of claim 2, wherein the parasitic effect is a change in pattern density. The method of claim 2, wherein the parasitic effect is an inconsistency in etching. The method of claim 2, wherein the parasitic effect is an inconsistency in polishing. The method of claim 2, wherein the parasitic effect is reduced in volume. The method of claim 1, wherein etching the polymerizable material changes the nanotopography and roughness of the first surface. The method of claim 1, wherein the desired shape characteristic of the second surface is planar. The method of claim 1, wherein the desired shape characteristic of the second surface is non-planar. The method of claim 1, wherein placing the polymerizable material between the same plate and the first surface according to the droplet pattern further comprises: placing a first polymerizable material having a first etching rate And placing a second polymerizable material having a second etch rate; and adjusting the droplet pattern to compensate for the first etch rate and the second etch rate. The method of claim 11, wherein the first etch rate and the second etch rate are different. The method of claim 1, wherein the evaluation of the nanotopography of the first surface and the desired shape characteristic of the second surface to provide the droplet pattern further comprises: evaluating the nano surface of the first surface A difference between the meter topography and the desired shape characteristic of the second surface to provide a height correction map; providing a density map based on the height correction map; and utilizing the density map to determine the drop pattern. An embossing lithography system for forming a desired nanotopography (nanotopography) a surface method comprising: determining a nanotopography of a surface; evaluating the nanotopography of the surface to determine the nanotopography of the surface compared to a desired nanotopography Height correction; providing a density map based on the height correction of the nanotopography of the surface compared to the desired nanotopography; determining a droplet pattern based on the density map; a droplet pattern placing the polymerizable material between an imprint lithography template and the surface; contacting the template with the polymerizable material; curing the polymerizable material; etching the polymerizable material to provide the desired nanometer The surface of the topography. The method of claim 14, further comprising determining at least one parasitic effect and adjusting the droplet pattern to compensate for the parasitic effect. The method of claim 14, wherein the desired nanotopography is planar. The method of claim 14, wherein the surface is non-planar and etching the polymerizable material provides the planar topography of the surface while maintaining the nominal non-planar surface. A method of forming a planar surface using an embossing lithography system, comprising: determining a nanotopography of a surface; evaluating the nanotopography of the surface to determine a droplet pattern to Providing the planar surface for a first polymerizable material having a first etch rate and a second polymerizable material having a second etch rate; placing the first polymerizable material and the first according to the droplet pattern a second polymerizable material between an imprint lithography template and the surface; contacting the template with at least one of the first polymerizable material and the second polymerizable material; curing the first polymerizable material and the first At least one of two polymerizable materials; etching at least one of the first polymerizable material and the second polymerizable material to provide the planar surface. The method of claim 18, further comprising determining at least one parasitic effect and adjusting the droplet pattern to compensate for the parasitic effect. The method of claim 18, wherein the evaluating the nanotopography of the surface to determine a droplet pattern further comprises: evaluating the nanotopography of the surface to determine the nanotopography of the surface a height correction of the planar surface being formed; providing a density map based on the height correction; and determining the droplet pattern based on the density map.