JP3396846B2 - Pattern formation method - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to molecules capable of adhering to the surface of a substrate in various conformations, patterning layers of such molecules by switching from one conformation to another. The invention relates to a method and the use of such patterned layers for lithography, data storage and display technologies.

[0002]

BACKGROUND OF THE INVENTION The dramatic advances in computer technology over the last 40 years have been due to an incomparable development beyond the three basic hardware elements: storage, processor, and display. In all three areas, the technology and science of surface structuring is of vital importance. The trend toward miniaturization and densification, coupled with improved performance, reliability, and productivity, increasingly requires good control of surfaces and interfaces down to the molecular or atomic level.

Currently, the design criteria for integrated circuits and storage devices are so small that some of the most important conventional structuring technologies are approaching their theoretical limits. For example, standard optical lithography is limited to about one-half wavelength and greater than about 140 nm for ultraviolet radiation. The bit size of the CD-ROM is limited to about 0.5 μm because current light emitting diodes emit red light with a wavelength of 800 to 1000 nm. Clearly, new technologies are needed to further reduce design criteria.

Regarding the display technology, since the panel design tends to be flat, a large matrix
The need for addressable pixel arrays is increasing. The technical issue here is energy efficiency, yield, and cost, not miniaturization. Liquid crystal displays (LCDs) currently play a major role in flat panel technology. In the LCD cell, the light transmission is changed by supplying an appropriate voltage. Thin film transistor (T
An array of FT) turns on and off individual LCD cells to achieve excellent contrast. However, this method is expensive and the TFT-LCD is correspondingly expensive. In addition, LCDs generally suffer from poor energy efficiency because they must be illuminated by an external light source, i.e. various colors obtained by passing white light through a filter. Because of these shortcomings, the display industry has a great deal of interest in technologies that may replace LCD technology.

Although light emitting diodes (LEDs) are more energy efficient than LCDs, currently available LEDs are too expensive for large display panels. Therefore,
Current R & D activities in this field are particularly focused on organic LEDs (OLEDs), which are promising for low cost mass production.
For an overview of OLED design and characteristics, see J. R. JR Sheats, H.M. Antoniadis (H. Anto
niadis), M .; M. Hueschen, W. W. Leonard, J. Miller,
R. R. Moon, D.M. Roitman (D. Roitma
n), and A. Stocking (A. Stocking), "Orga
nic Electroluminescent Devices ", Science, Vol.27
3, p.884, 1996. Mainly OLE
D is composed of a polymer layer sandwiched between a metal electrode and a transparent semiconductor electrode. The major drawbacks of current OLEDs are their durability due to chemical interactions with the environment and deterioration due to electron injection at excessively high energies required due to poor matching of the polymer's electronic properties to the electrode material. It has a short life.

However, it is possible to influence the electron injection ability by modifying the molecules adjacent to the interface between the electrode and the polymer. For example, A. Haran (A. Har
an), D.I. H. DH Waldeck, R.W. R. Naaman, E. E. Moons, and D.M. D. Cahen, "The Dependence of
Electron Transfer Efficiency on the Conformational
Order in Organic Monolayers ", Science, Vol.263,
p.948-950, 1994, the effect of a monolayer of octadecyltrichlorosilane (OTS) molecules on the electron transfer (ET) process from a silicon electrode to an aqueous electrolyte solution is described.

The OTS layer can be converted from one conformation to another by heating. Different conformations can result in the bending or bending of certain molecular bonds.
ng) corresponds to the different geometry of the molecule.

The inventor of the present invention has found that the current-voltage characteristic is OT.
Not only the degree of coverage of S molecules,
It was found that it also depends on the conformation of the OTS molecule. In one experiment, when a layer was converted from one conformation to another, the reverse current at a voltage of 0.2 V changed from 4.5 μA to 0.2 μA.

Research towards controlled fabrication of microstructures has been greatly facilitated by the recent development of scanning probe microscopes (SPMs). Many SPM probe tips can be used not only to monitor changes in the surface structure of a sample with atomic or near-atomic resolution, but also to modify the surface on a similar scale. Confirmed by example. For example, T.W. A. TA Jung, R. R. RR Schlit
tler), J. K. JK Gimzewski,
H. H. Tang, and C.I. Joachim (C. Joac
him) in Science, Vol.271, p.181, 1996, SPM
It has been shown that the effect of the tip is that each molecule can be moved to a new predetermined fixed position, or modified without changing the position, or both. In pursuit of these studies, molecular flexibility was found to play an important role in such manipulations.

A fixed sequence of molecular layers on a substrate forms, for example, a Langmuir-Blodgett (LB) film or a self-assembled monolayer (SAM) film, or performs cooperative self-assembly, or sublimation or conformation. It is formed by molecules that are attached by epitaxy.

A molecule can exist in various conformations that are characterized by the (meta) stable orientation and / or position of the various entities that make it up. The various entities of these molecules are made up of sub-entities of atoms similar to individual atoms or molecules that are more strongly bound to each other to the atoms of other entities. The connection between the individual entities is often a unimolecular bond that can serve as the axis of relative rotational movement of the entities. Switching between the various conformations is usually done by rotational realignment of such entities. Molecules that are structured into such entities are standard in organic chemistry.

[0012]

A first object of the present invention is to provide a class of molecules that can be attached to a substrate in different conformations. A second object of the invention is to provide a layered medium of molecules that can be attached to a substrate in different conformations. A third object of the present invention is to provide a method for forming a predetermined pattern on a layered medium composed of molecules that can be attached to a substrate in different conformations.

[0013]

The present invention, by virtue of the presence of several stable or metastable conformations, determines these conformations individually or within a range by external influences and switches ( immobilizing switchable molecules to a substrate.

Appropriate combinations of different entities allow the design of molecules with one conformation that meets the requirements of certain applications and other conformations that are significantly different. Technically important characteristics that undergo such changes include:
These include chemical activity, conductivity, color, molecular size, and adhesion to the substrate. On the contrary, these changes are associated with different types of identification (in
The terrogating technique can be used to identify the conformation of certain molecules or layered media of such molecules. The different conformations of such molecules are defined by the minimum of the system molecule / substrate potential energy in the coordinate coordinates. Generally, when plotted as a function of this coordinate, the associated coordination coordinates can be defined for each transformation between the two conformations such that the potential energy has at least two characteristic minima. The location and depth of these minima determine the structural arrangement of each of the entities in these conformations and their stability to thermal excitation and / or external influences. The deepest minimum corresponds to the stable conformation of the molecule. All other conformations are metastable. The energy barrier between the corresponding energy minimum and its vicinity is 2 at room temperature.
Molecules can exist in a metastable conformation indefinitely if sufficiently large compared to thermal energy up to 5 meV.

External influences that cause conformational switching include mechanical forces that deform molecules to the extent that they rapidly move to another conformation, such as macroscopic switches, and other molecules The emission of light or electrons that raises to an excited state so that it collapses to the conformational ground state, the height or width of a particular energy barrier or the extent to which a molecule flips to another conformation due to thermal excitation or tunneling. There is an electric field supply that reduces both. In the following, the term "conformation" shall refer only to the conformation of a molecule that is switchable by external influences.

The present invention provides a class of molecules that can be attached to substrates in different conformations. At least one of these conformations occurs and / or is stabilized near the substrate surface. Furthermore, these molecules are switchable between at least two of their conformations by external influences provided by the structuring means.

For example, C of (100) orientation under ultra-vacuum
Newly deposited Cu-tetra- (3, on the u crystal surface
5-di-tert-butylphenyl) porphyrin (C
The u-TBP-porphyrin) molecule remains in a conformation similar to that of the free molecule. In this conformation, the peripheral entities of the molecule are oriented perpendicular to the plane of the central entity, which is far enough from the substrate surface that it is almost unaffected by the forces of interaction. However, when pushed down by the tip of the STM, this central entity is pulled strongly towards the substrate due to the attractive force, here the adhesive force, and remains in this second state when the tip is removed. That is, the system Cu-TB
P-porphyrin / substrate is bistable, unlike free molecules.

The molecule, which is the first embodiment of the invention, exemplified by Cu-TBP-porphyrin, is composed of different entities and can be attached to a substrate by physical adhesion and / or chemical bond formation. This means that even though these molecules are free to move along the surface of the substrate, their position is at least 1.
It has the advantage of being fixed in one dimension. In addition, the substrate has the advantage of balancing the forces exerted on the molecules during switching or acting as electrodes when the molecules are exposed to an electric field. This molecule also has the property that one of its conformations is stable only when the substrate is present. Specifically, one of the entities has a negligible attractive force acting between the substrate and that entity during the switch in the first conformation but is negligible in the second conformation after the switch. The position with respect to the substrate is changed so that it becomes stronger enough to be stably attached to the substrate surface. This has the advantage that molecules that exist in only one conformation in free space are bistable attached to the substrate and can therefore be used in various applications described below. The dramatic change in interaction with the substrate is that the molecule is completely immobile in the substrate-dominated conformation, but is otherwise movable along the substrate surface and vice versa. It also has advantages.

The second embodiment, the molecule, has the advantage that it is fixed in a position on the substrate in at least one conformation and can therefore be individually addressed by means of identification or structuring. In particular, the structuring means is
Molecules can be selected to switch from one conformation to another. The immobilization of molecules also has the advantage that the conformation of a particular molecule or the conformation of several such molecules can be locally and individually determined by the identification means.

The molecule of the third embodiment has the advantage that it can be repeatedly switched between the two conformations in sequence, which makes it suitable for display or read / write storage.

The fourth embodiment, the molecule, has the advantage that it can be structured according to a clear and therefore feasible design concept. That is, the central entity can be designed to dominate the observable physical and chemical properties, while one or several peripheral entities define the entire structure of the molecule, or are implicitly central. A "leg" can be formed that protects the entity or connects the molecule to the substrate, or a combination thereof can be implemented.
A further advantageous feature of this molecule is that the distance of the central entity from the substrate can be varied during the switching process, for example by tilting the peripheral entity from vertical to an oblique position. As a result, the molecule is able to move along the substrate surface in the first conformation, but is completely fixed in the second conformation. Moreover, the molecule is easily removed by the solvent in the first conformation and is taller than in the second conformation. Also, the properties of the electronic state of the molecule differ significantly between the two conformations. Therefore, the optical properties of molecules such as fluorescence differ dramatically between the two conformations.

The envisaged application of the switchable, attachable molecules described above requires coating, control or modification or a combination thereof for areas (much) larger than the size of the individual molecules. Therefore, the present invention provides a layered medium composed of these molecules.

In the form of a complete monolayer, the layered medium of the fifth embodiment of the present invention has the advantage of forming a dense coating that effectively protects the underlying substrate. Incomplete monolayers, on the other hand, have the advantage that a portion of the substrate can be exposed and this portion can be accessed by modifying the medium without removing the layered medium.

The layered medium of the sixth embodiment has the advantage that the molecule is fixed in any conformation. This is preferred in applications where the molecule is used as an information carrier or reversible switching element, as the molecule can be reproducibly addressed.

The layered medium of the seventh embodiment has the advantage that the molecules of the imperfect monolayer continuously change position in the horizontal direction due to thermal excitation. Therefore, part of the substrate is not permanently coated with molecules. That is, this part is exposed to the environment for a certain period of time and is attacked by the reforming means during this period. On the other hand, in the conformation where the molecules form a complete monolayer, the substrate surface is permanently shielded from environmental influences.

The eighth embodiment, a layered medium, has the advantage of functioning as a local electrical switch that controls the electron transfer of molecules from the substrate to the medium located on the layered medium and vice versa. Switching is enabled by the electronic level placement of molecules in a layered medium that facilitates the emission of electrons from or to the substrate in one conformation, but is detrimental to emission in the other conformation. .

The application of the layered medium of the invention is an important application of the layered medium, since the incorporation of the layered medium into the OLED provides an electron injection layer whose injection capacity can be switched on and off by the structuring means. For example, the structuring means is O
A short voltage pulse can be applied to the two electrodes of the LED. Alternatively, for example, piezoelectrically generated pressure pulses can cause the switching. The function of the switchable electron injection layer is similar to that of thin film transistors used in current active LCDs.

Many anticipated applications of the layered media of the present invention require the production of a predetermined pattern in the layered media and / or the underlying substrate. Therefore, the present invention provides a preferable method for performing such pattern formation.

Embodiments of the present invention disclose various variations of the process of structuring the layered medium and, optionally, the underlying substrate.

In another embodiment of the present invention, a method of forming a pattern by locally exerting one or several external influences in a controlled manner is disclosed. These external effects include mechanical forces that deform the molecule to the extent that it can switch to different conformations, such as macroscopic switches, and collapse of the molecule to its other conformational ground state. Irradiation of light or electrons that pulls the molecule into a possible excited state, or the supply of an electric field that reduces the height and / or width of a particular energy barrier to the extent that the molecule is turned into another conformation by thermal excitation or tunneling. is there.

The method according to the tenth embodiment of the present invention is
It has the advantage of forming a predetermined pattern in a layered medium consisting of regions in which the molecule is in one conformation and other regions in which the molecule is in the other conformation. Layered media are preferably fabricated such that all molecules are initially in the same conformation. The regions to be subsequently converted to other conformations are selected in the first stage by suitable structuring means and exposed in the second stage to the environment influencing them.

The method according to the eleventh embodiment of the present invention is
Advantageously, molecules in any one conformation are selectively removed from the substrate, leaving behind a predetermined pattern of regions where the substrate is coated with the layered medium and other regions where the substrate surface is uncoated. Have. The first molecule removing means is used for this purpose, and a solvent or a wet or dry etchant can be used as the molecule removing means.

The method of the twelfth embodiment is such that the surface of the substrate treated by the method of the tenth and optionally the eleventh embodiment is exposed to a modifying means that attacks unprotected portions of the substrate surface. This has the advantage that the pattern is structured. The modifying means can remove material from, or deposit material on, the unprotected portion of the substrate surface. This processing step is optional when the layered medium of the seventh embodiment is used, as this layered medium allows the modifying means to access the substrate.

The method of the thirteenth embodiment has the advantage of removing the residue of the layered medium from the substrate, leaving behind a predetermined pattern on the surface of the substrate. A second molecular removal means can be used for this purpose. This means, like the first means, can be a solvent or a wet or dry etchant, but must have the ability to remove all of the molecules of part of the layered medium or that were part of the layered medium. I have to. Complete removal has the advantage that the substrate can be further processed if desired, for example in the manufacture of integrated circuit electronic elements.

The fourteenth embodiment, patterning with a movable inductive stylus, has the advantage that very small portions of the layered media on the substrate can be selected and switched. This allows a correspondingly small structure to be drawn on the substrate. It is also an advantage of this method that the shape of the pattern can be changed freely by reprogramming the stylus path along the substrate. External influences of the stylus include, for example, mechanical pressure, electric field or exposure to a beam of electrons or photons. Therefore, this patterning method is particularly suitable for applications requiring sufficient flexibility, such as testing in research and development.

The pattern formation by the stamp, which is the fifteenth embodiment, has the advantage of being very simple. In particular, it is possible to form all patterns at the same time, even if the patterns have a very complicated structure. Moreover, the pattern can be easily duplicated in large quantities. Therefore, this pattern forming method is suitable for mass production of, for example, a compact disk type read-only storage carrier using the layered medium of the sixth embodiment as a storage medium.

The pattern formation by the actuator array, which is the sixteenth embodiment, has the advantage that the pattern forming means, that is, the actuator array, remains in a fixed position with respect to the substrate. It is also an advantage of this method that the shape of the pattern can be freely changed by properly addressing the array element to be activated. In particular, since no mechanical movement is required, high speed processing is possible if several elements are operated in parallel at the same time. Therefore, this pattern forming method is suitable for an application in which a reversible pattern change is frequently performed, for example, when it is used as a switching element of a read / write storage device or a display device.

The elements of the array are, for example, electrodes,
It can be a light source such as a piezoelectric pestle, or an illuminated aperture with a shutter. The electrodes are
It has the advantage of locally exposing the molecules of the layered medium to an electric field or an electron beam. Piezoelectric pestle has the advantage of being able to provide mechanical pressure or to send shock waves to the medium. The light source has the advantage of bringing the molecules of the layered medium into excited electronic states that collapse into a new conformation.

Patterning with an illumination or particle beam device, the seventeenth embodiment, has the advantage that commercially available lithographic devices can be used for patterning.

It is also possible to combine the methods of the fourteenth to seventeenth embodiments in a preferred manner.
For example, an array of SPM chips can be used in the patterning process to increase throughput.

The pattern identification according to the 18th embodiment is
It has the advantage that the conformation of a molecule in a region can be determined by the same means used for patterning. This means that the formed pattern can be somehow corrected by spots in the wrong position (potent).
It also has the advantage that it can be controlled with respect to ial error). Another major advantage is the ability to determine the shape of existing patterns required for the reading process when using layered media as the storage medium.

The present invention is directed to applications of monolayers at the interface with substrates for specific monomolecules, molecular assemblies, and data storage, as a new class of resists, or in connection with various molecular devices. The main operation is
Switching between molecular conformations formed by designing the functionality of the molecule, with the substrate in contact with the interface. Specifically, to use the bistability of the molecule obtained by designing the functionality taking into account the relevant properties of the interface-facing substrate. The described embodiments include the application of positive and negative resists, and ultra high density storage.

The invention further provides methods of addressing and switching molecular properties, in particular electron transfer and photon emissivity.

The activation energies and mechanisms that switch a molecule from one conformation to another can be selected depending on the structure of the molecule, its internal flexibility, and the overall interaction of the molecule with the substrate. The molecule / substrate system can be optimally tuned when the switching potential barrier is well above the thermal energy kT, where T represents a reliable operating temperature.

This molecule can be synthesized by existing methods. The immobilization of this molecule on the surface of the substrate allows the use of micro- and nano-order manufacturing equipment and any subsequent processing methods. The application of this molecule in the molecular layer as a new type of resist allows the formation of nanometer scale patterns. The disclosed molecules, layered media, and methods enable wide applicability and various combinations of other established and developing methods.

The examples presented herein include resist applications, ultra high density storage and display applications. The present invention presents a method for addressing, switching between locations on a substrate and for identifying molecular properties, in particular adhesion to the substrate and electron transfer efficiency.

The various molecules belonging to the class of molecules disclosed herein, as well as the various disclosed methods, allow a wide range of applications and combinations with other techniques already established or under development.

[0048]

BEST MODE FOR CARRYING OUT THE INVENTION Various embodiments of the present invention will be described.
This will be explained below. FIG. 1 (a) is a schematic diagram of a molecule composed of a first entity 1, here a central entity, and two second entities 3, peripheral entities. The first entity 1 is coupled to the second entity 3 via a connection 2. The entity 3 is in close contact with the substrate 4 by the second attractive force 5. The molecule is in the first conformation 18, with the central entity 1 and the peripheral entity 3 oriented perpendicular to each other. This orientation is energetically favorable with respect to the directionality of the connection 2. The central entity 1 is located at a distance from the substrate 4, in which position the first attractive force 6,
Here, the short-range adhesion of the substrate 4 acting on the central entity 1 is small and is therefore not shown. Second
The interaction between the molecule and the substrate 4 due to the attractive force 5 is limited to the part of the peripheral entity 3 in the immediate vicinity of the substrate surface. Therefore, the first conformation 18 is approximately equal to the stable conformation of the molecule in free space or solution.

FIG. 1 (b) shows the molecule in a second conformation 19 with the peripheral entity 3 laterally tilted so that the central entity 1 approaches the surface of the substrate 4. In this case, the central entity 1 is under the influence of a strong attractive force 6 towards the substrate 4. The position of the central entity 1 is determined by the balance between the additional attractive force 6 and the restoring force generated by the inclination of the connection 2. The second conformation 19 is
Not present if the molecule is in free space or in solution.
The tilt angle is used as the corresponding coordination coordinate for this molecule.

FIG. 1c schematically shows the conversion, ie the switching from the first conformation 18 to the second conformation 19 under the influence of the stylus 7, here the SPM tip. This module is part of a layered medium consisting of a complete monolayer 15 of molecules on a substrate 4. SPM chip 7
Causes the selected molecule to switch, for example by applying mechanical pressure to the molecule.

FIGS. 2 (a) and 2 (b) show other types of molecules in the two conformations 18 and 19. This molecule consists of a first entity 1, a second entity 3 and two third entities 8 linked together in the form of a closed chain by four connections 2. Here, the four entities 1, 3, 8 are identical. FIG. 2 (a) shows that the inclined shape of the connection 2 is energetically favorable for this molecule, so that the entities 1, 3, 8 are in the first conformation 18 arranged in a parallelogram shape. Indicates a molecule. Second entity 3
Are in close contact with the substrate 4 via the second attractive force 5. The other entities 1 and 8 are too far from the substrate 4,
Does not receive a large attractive force.

In FIG. 2 (b), the first entity 1 and the second entity 3 lie flat on the substrate 4, and the third entity 8 lies above the first entity 1 and the second entity 3. Shows the molecule in the second conformation 19 lying in FIG. The first entity 1 and the second entity 3 respectively receive attractive forces 5 and 6 provided by the substrate 4. The third entity 8 is pulled to the entities 1 and 3 by the cohesive force 9. The shape of the molecule in the second conformation 19 suggests a strong deformation of the connection 2. The elasticity obtained is balanced by the attractive force 6 and the cohesive force 9. Connection 2
One of the tilt angles can be chosen as the coordination coordinate for this type of molecule.

FIG. 3 is Cu-tetra- (3,5-di-tert-butyl-), which is one of the molecules which can be present on the substrate 4 in the two conformations 18 and 19 according to FIG. 1 shows the structural formula of phenyl) porphyrin (Cu-TBP-porphyrin). Central entity 1 is the Cu-porphyrin moiety. Peripheral entity 3 is four butylphenyl groups. Connection 2 is a directivity (di) between C atoms of central entity 1 and peripheral entity 3, respectively.
rectional) consists of molecular bonds. Peripheral entity 3
Can rotate about these CC axes, and the average tilt angle is the relevant coordination coordinate of this molecule.

In the first conformation 18, as shown in FIG. 1 (a), the peripheral entity 3 is rotated 90 degrees about the CC axis from the plane of the drawing. Therefore, the peripheral entity 3 prevents the central entity 1 from approaching the substrate 4 beyond the distance given by the spatial extent of the peripheral entity 3 with respect to its CC axis. Second
In conformation 19, the peripheral entity 3 is oriented substantially parallel to the plane of the figure, thereby bringing the central entity 1 and the substrate 4 into contact, as shown in FIG. 1 (b).

FIGS. 4 (a) and 4 (b) schematically illustrate the energy potentials E of the two molecules shown in FIGS. 1 and 2, respectively, as a function of the respective coordination coordinates φ. It is shown in. Dashed curve 10
, And the solid curve 12 represent the free space and the potential of the molecules adjacent to the substrate 4, respectively. Figure 4 (a)
Then, the broken line curve 10 indicates the minimum potential 11 and the two maximum potentials 14, and the solid line curve 12 indicates the three minimum potentials, that is, one relatively high minimum potential 11 and two relatively low minimum potentials 13. Have.

The single minimal potential 11 of the dashed curve 10 in FIG. 4 (a) has only one energetically favorable orientation in free space, which is the orientation of the first conformation 18. Is shown. When attached to the substrate 4, two more minimal potentials 13 are obtained by the first attractive force 6 acting between the substrate 4 and the central entity 1. The minimum 13 has the maximum potential energy 14
In the case of, the value of the related coordination coordinate φ that is the least preferable for the free molecule is obtained. The minimum 13 is the second conformation 1
Corresponds to 9. Some potential minima 13, 11
The presence of a indicates that the molecule can switch between two or more stable or metastable conformations.

Stable conformations in free space for molecules of the type shown in FIG. 2 are shown in FIG. 2 (a). The conformation shown in FIG. 2 (b) is also possible in principle by the cohesive force 9. The resulting potential curve 10 is shown by the dashed curve in FIG. 4 (b) and thus already has unequal minima 11 and 13 in free space, but the second minima 13
Is shallow. Thus, thermal excitation prevents the molecule from staying in the corresponding conformation for an extended period of time. The substrate 4 stabilizes this second conformation by the first attractive force 6. This is the fourth
This is indicated by a deep minimum 13 in the solid curve 12 in FIG.

FIGS. 5 (a) to 5 (c) show a layered medium having switchable molecules arranged as a complete monolayer 15 on a substrate 4 and a predetermined pattern to be formed. 3 shows three devices that selectively switch molecules in a region. The molecule is switched from the first conformation 18 to the second conformation 19. The two conformations are indicated in the figure by the lines "H" and "/-/", respectively.

FIG. 5A shows pattern formation using a stylus 7 such as an SPM chip. When the stylus 7 is moved horizontally in close proximity to the monolayer 15, the contacted molecules move from the first conformation 18 to the second conformation 19
Can be switched to. To leave a given region in the first conformation 18, while moving over these selected regions,
The stylus 7 can be lifted.

FIG. 5B shows pattern formation using the stamp 20 having the protrusion 21. Monolayer 15
The predetermined area of is switched. The protrusion 21 is
Mechanical pressure is applied to the region of the layered medium to switch the molecules in the region of the monolayer 15 from the first conformation 18 to the second conformation 19.

FIG. 5 (c) shows an individual actuator 3
1 shows patterning using an actuator array 30 of 1. A predetermined region of the monolayer 15 allows molecules in the monolayer 15 to move from the first conformation 18 to the second conformation 19
Exposed to the electric field. The area to be switched is selected by the electrical switch 32 connecting the individual actuator 31 to the voltage supply line 33. The voltage supply line 33 is held at the voltage US with respect to the second voltage supply line 34 connected to the substrate 4.

FIG. 6 and FIG. 7 show a process for forming a pattern on the surface of the substrate 4 in a lithography process.
6 illustrates the use of a monolayer of attachable and switchable molecules. In this application example, the monolayer 15 functions as a resist.

FIG. 6 shows conformations 18 and 1 such as molecules in the “H” conformation 18 of FIG.
9 shows the various steps required for a layered medium consisting of molecules in both 9 and a complete monolayer 15.

FIGS. 6 (a) and 6 (b) show a pattern, for example, using one of the devices shown in FIG. 5 for switching the molecule from the first conformation 18 to the second conformation 19. A monolayer 15 of molecules on the substrate 4 before and after formation is shown. Sixth
In the next step shown in FIG. 6C, the molecules of the first conformation 18 are removed by the first molecule removing means. Next, the sixth
As shown in FIG. 3D, the substrate 4 is exposed together with the remaining molecules in the second conformation 19 to the modifying means 42 that selectively attacks the uncoated region of the substrate 4. Here, when the desired modification level, which is the predetermined etching depth shown in FIG. 6 (d), is reached, the modification process is terminated by removing the layered medium from the modification means 42, and the residual molecules are separated. When the molecular layer 15 is removed by the second molecule removing means,
As shown in FIG. 6E, a raised pattern remains on the surface of the substrate.

FIG. 7 shows an alternative lithographic process that can be applied to a monolayer 15 of molecules that are initially moveable and in a first conformation 18 that forms an imperfect monolayer 15 on the substrate 4. Show. The second attractive force 5 acting between the molecules in the first conformation 18 and the substrate 4 is sufficiently small so that the substrate 4 may be temporarily protected from being partially covered with the molecules.
Along the axis, molecules can undergo thermal motion.

FIGS. 7 (a) and 7 (b) show a pattern, for example, using one of the devices shown in FIG. 5 to switch the molecule from the first conformation 18 to the second conformation 19. A monolayer 15 of molecules on the substrate 4 before and after formation is shown. In this second conformation 19, the molecules lie flat on the substrate 4,
They are connected by attractive force (5, 6). This second conformation 1
At 9, they completely cover a given area of the substrate 4.

In the next step shown in FIG. 7C, the substrate 4 having the monolayer 15 of molecules in the two conformations 18 and 19 is placed on the surface of the substrate in which the molecules in the first conformation 18 are present. The area of the substrate 4 that is floating is exposed to the modifying means 42 that selectively attacks it. The thermally induced movement of the molecules causes the modifying means 42 to reach all locations within the region of the molecule in the first conformation 18. The molecules in the conformation 18 are only loosely bound to the substrate 4 and are therefore removed from the substrate 4 by the modifying means 42. But the second
Molecules in the conformation prevent the substrate 4 from being altered. The modification need not be a material removal step, but may be a step of adding material, such as by using the molecules in the second conformation as a mask to grow a layer of the required material.

The subsequent steps are the same as the first step shown in FIG. 6, that is, the modifying means 42 is removed, thereby stopping the etching step, and further removing the molecules in the second conformation 19. To do. Actually, the difference between the two steps is that the monolayer 15 remaining in the first conformation 18 shown in FIG.
Is a step of removing these portions. This process is
In the case of the second step, the molecules in the first conformation 18 are transferred to the substrate 4
Unnecessary since it is movable on the surface of the substrate and therefore does not permanently prevent the substrate 4 from being attacked by the modifying means 42.

FIG. 8A shows a substrate 4 as a storage medium.
Figure 6 shows the use of a layered medium with attachable and switchable molecules in the form of a monolayer with two conformations 18 and 19 above. Information is stored in changing conformations 18, 19. Since the conformers 18 and 19 can affect dimensions, electrical resistance, reflectivity, transmissivity, magnetic properties, etc., modifying one or some of these properties in the region of the layered media is It can be used to retrieve the information provided. The pattern can be formed or written using one of the devices shown in FIG. For the purpose of identifying, that is, reading the information stored in the pattern, here, a scanning tunneling microscope (ST
The stylus 7, which is the tip of M), is moved close to and moved along the monolayer 15 preferably at a fixed distance.

FIG. 8 (b) schematically shows the relationship between the tunnel current It and the time t. The tunneling current varies between two different values because the probability of electron tunneling depends sensitively on the molecular conformations 18 and 19 underneath the tip of the tip. The bit values "1" and "0" can easily be assigned to two different values of the tunnel current It. FIG. 9 schematically shows a cross-section of an OLED which, unlike previously known OLEDs, now incorporates a layered medium consisting of a monolayer 15 of molecules in two conformations 18 and 19. The other elements of the OLED are, from top to bottom, the transparent electrode 60, the continuous light emitting polymer layer 61, and the conductive substrate 4. The substrate 4 and the transparent electrode 60 are connected to the voltage US via the voltage supply lines 33 and 34.

The figure also shows the electrons 62 injected from the substrate 4 and the photons 63 emitted from the polymer layer 61. Board 4
Functions as an electron injection counter electrode for the transparent electrode 60. The electrons injected into the polymer layer 61 lose energy due to the emission of photons 63. The probability of injection is the polymer layer 6
1 sensitively depends on the characteristics of the interface between the substrate 1 and the substrate 4, that is, the electron transfer (ET) ability of the monolayer 15. Electronic transfer (E
T) Ability is determined by the electronic state of the molecule. The electronic state of the molecule differs due to the different conformations 18 and 19 of the molecule. Therefore, by appropriately designing the molecules in the monolayer 15, each molecule can be assigned a first conformation 18
To a second conformation 19
The LED is switched from a highly efficient light emitting state to a dark state or vice versa. Switching between conformers 18 and 19 can be performed in a manner similar to that by the device described in FIG. 5, eg by applying a short voltage pulse.
By appropriately structuring electrodes 4 and 60, the OL
The electron transfer (ET) capability of a given area of the ED can be turned on and off, thus turning on and off light emission. Such capabilities are useful in OLED display applications and provide similar functionality to that of thin film transistor switches in active LCDs.

In summary, the present invention is based on a molecule divisible into several entities 1,3. The entities 1, 3 are connected somewhat flexibly, for example by coupling electron trajectories 2. Entities 1, 3
Can be arranged in stable or metastable orientations in mutually different orientations, the different orientations corresponding to the conformations 18 and 19 of the molecule. The stable orientation is given by the minimum of the potential energy of the molecule with respect to the coordination coordinates of different conformations 18 and 19, or the nature of the coordination in those conformations. The molecule is stably attached to the desired surface of the substrate 4 in at least one of the different conformations 18 and 19. The switching can be done by relative rotation and / or translation of the entities 1, 3 with respect to each other and / or to the substrate 4.

In addition to the embodiments described, in data storage, lithography, molecular electron transfer, and switching conformations of molecules in light emission from photoelectric devices, the conformations generally determine the physical and chemical properties of the molecular system. It is important to show that. Thus, the described methods for molecular conformational design, integration, and addressing can be combined with other physicochemical detection mechanisms. The devices and methods described above can be combined with each other and with other techniques to assemble detection or nanoscale functional structures. Specifically, the above technique is applicable to any detection method such as a cantilever type sensor, a vibration reed magnetometer, an NMR, an ESR, an immunosensor, a waveguiding and a diffractive optical sensor, a single photon detection / single molecule spectroscopic analyzer. Can be combined. Also, alternative characteristics can be controlled or switched by the disclosed method. In general,
For example, chromophority, photochromic action, electrochromic action, catalytic action,
Enzyme action, medicinal action, specific reactivit
y), spin level, immunity, NMR labels, hormones, any chemical functionality, conformational switching /
May be combined with activation. By way of example, patterning or control of superconductivity of organic superconductors, eg control of selective chemical reactivity by groups which are hidden in one conformation and exposed in one conformation in another conformation, eg the magnetism of the layer, The magnetic properties of the layer, such as light reflectance,
There are changes in electrical characteristics. A mixture of designed coordination systems can be used to reveal properties. Using the example of specific reactivity hidden in the coordinately inactive form above, various reaction precursors were identified and synthesized (integrat
ed) can. It has been demonstrated that integration techniques such as particle beam, optical lithography, stamping, etc., as specifically described in this example, as well as coordination configuration excitation, assembly and integration techniques, such as contact force, can be used. There is. Also, advanced "bottom-up" integration techniques may be used, as well as advanced exploratory means of lithographically integrating functional structures such as chemical self-assembly techniques, LIGA.
Any writing medium can also be used as a reading medium. In general, any reading mechanism can be used.

[Brief description of drawings]

FIG. 1 is a molecule of the present invention having a central entity and a peripheral entity in a first stable conformation (a), a molecule having a central entity and a peripheral entity in a second stable conformation (b), And 3 in different stable conformations
FIG. 3 is a schematic diagram showing a substrate (c) having one molecule and one stylus.

FIG. 2: Molecules of the present invention with four equal entities in the first stable conformation (a) and molecules with four equal entities in the second stable conformation (b). ) Is a schematic view.

FIG. 3 is a diagram showing a structural formula of Cu-tetra- (3,5-di-tert-butylphenyl) porphyrin (Cu-TBP-porphyrin).

FIG. 4 Free space (broken line) and the vicinity of the substrate surface (solid line)
FIG. 3 is a diagram showing potential energies of molecules in a specific coordination coordinate, where (a) potential energy causes new potential wells in the vicinity of the substrate, and (b) potential energies exist in the vicinity of the substrate. It is a figure which shows that the potential well of is strengthened.

FIG. 5 shows molecules of selected regions of a layered medium of the present invention,
(A) SPM chip, (b) stamp, or (c)
FIG. 6 shows a device for switching from one conformation to another conformation by an electric actuator array.

FIG. 6 shows step by step the process of structuring the surface of a substrate with a complete monolayer of switchable, attachable molecules.

FIG. 7 shows step by step the process of structuring the surface of a substrate with an imperfect monolayer of switchable, attachable molecules.

FIG. 8A is a view showing an apparatus for identifying a molecular conformation of a layered medium by a movable stylus which is an STM chip according to the present invention, and FIG. It is a figure (b) which shows the change of a tunnel current when moving along.

FIG. 9 is a schematic diagram showing an OLED having a layered medium with switchable, attachable molecules that exist in two different conformations, one of which acts as an electron injection promoter.

[Explanation of symbols] 1st entity 2 connection 3 Second entity 4 substrates 5 Second attraction 6 First attraction 7 SPM chip 8 third entity 9 Cohesive force 15 monolayer 18 First conformation 19 Second conformation

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI H01L 29/28 (72) Inventor Jung, Thomas Clardenstraße, Tarville, Switzerland 2 (72) Inventor Schritter, Rat, Earl. Switzerland Hitenstraße, Schoenenberg, Country 7 (56) References A. Jung, et. al. , Controlled Room-Temperature Position of Individual Molecules: Molecular Flex and Motion, Science, USA, Jan. 12 181, 1996, 181-1, 271 ,. A. Jung, et. al. , Conformal idenification of individual absorbed mo le rules with the S ™, Nature, United Kingdom, April 17, 1997, 386, 696-698 Francesca Moresco, et. al. , Conformational Changes of Single Molecule Induced by Scanning Tunneling Microscopy Manipulation, Physical Rehearsal, Psycho Revitals, USA, 22nd March, 2001. 86, No. 4,672-675 (58) Fields surveyed (Int.Cl. ⁷ , DB name) G03F ⁷ /20-7/24 G03F 9/00-9/02 B82B 3/00 G03C 3/00 G03F 7/004- 7/04 G03F 7/06 G03F 7/075-7/115 G03F 7/16-7/18

Claims (7)

(57) [Claims] 1. A molecule comprising at least two types of entities connected to each other by at least one connection on a substrate, and having at least two different stable or metastable conformations. Arranging in one layer, selecting a region of the layer, structuring means for switching the molecule in the selected region from one of the conformations to another one of the above selected Exposing a region, wherein the at least two different conformations are identifiable by a different arrangement of the entity with respect to the substrate and / or with respect to the substrate, the first conformation of the conformations being Then, the molecule is attracted to the substrate by a second attractive force between the second entity of the entities and the substrate, The first entity has a position with respect to the substrate that has a first attractive force that is negligible compared to the second attractive force, and in a second conformation of the conformations, the first entity has the first attractive force. entity have a position bonding to the substrate by the first attraction,
The molecules are attached to the (100) -oriented Cu crystal surface.
Cu-Tetra- (3,5-di-tert-butyl phthalate
Phenyl) porphyrin molecule, and the structuring means is
From the group consisting of stylus, stamp and actuator
Selected characterized Rukoto pattern forming method. 2. Method according to claim 1, characterized in that the molecule is reversibly switchable between the first and second conformations. 3. The first entity has a central location in the molecule and the second entity comprises at least one peripheral entity movably connected to the first entity. The method according to claim 1, wherein 4. The method of any one of claims 1-3, further comprising removing a molecule in one of the conformations. 5. A pattern is formed on the substrate after the removing step by using molecules remaining at fixed positions of the substrate as a patterning mask.
The method of claim 4. 6. A method according to any one of claims 1 to 5, characterized in that the structuring means is a stylus . 7. A method for identifying a pattern in the layered medium or on the substrate, which is formed by the method according to claim 1 or 5, wherein the pattern is formed by using an identifying means including a stylus. How to identify.