EP0360337A2
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EP
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Method of and device for sub-micron processing a surface
Assignee: Koninklijke Philips NV
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Filing: 1989-09-15
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Granted: —
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Expires: 2009-09-15
Abstract
Abstract A method of and a device for sub-micron deforming a surface (15) is described, for example for the purpose of inscribing information. During scanning of the surface the tip (14) of a scanning tunneling microscope is held at a constant distance from the surface by means of a negative feedback control loop (18) which is controlled by a tunneling current (It) between the tip and the surface, and for forming a pit (21) in the surface (15) the control loop is deactivated and a tip height drive member (8) is energized by means of a control voltage (Vpz) whose amplitude increases as a function of time and which has a predetermined final value, such that the tip is lowered into the material.
Inventors
- 👤 Evert Jan Van Loenen
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 22:11
CPC Classifications
B; B82; B82B; B82B3/00; B82Y; B82Y10/00; B82Y30/00; B82Y40/00; G; G11; G11B; G11B11/00; G11B11/002; G11B11/007; G11B3/00; G11B9/00; G11B9/12; G11B9/14; H; H10; H10P; H10P76/00; G01; G01Q; G01Q80/00; Y; Y10; Y10S; Y10S977/00; Y10S977/84; Y10S977/849; Y10S977/855; Y10S977/856; Y10S977/902; Y10S977/932; Y10S977/943; Y10S977/947
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
249 words
A method of deforming a surface on a sub-micron scale by using a tip of a scanning tunneling microscope in which the drive means for moving the tip in a scanning direction parallel to the surface are used to cause the tip to describe a path in a plane parallel to the surface in accordance with the desired processing pattern in said surface, said tip, when describing said path, being held at a reference level at a constant distance from the surface by means of a first electric control voltage applied to a tip height drive member, said voltage being supplied by a negative feedback control loop which is controlled by a tunneling current between the tip and the surface, which current results from a constant tunneling voltage applied between the surface and the tip, characterized in that a surface deformation is brought about by interrupting the said negative feedback control loop, in that the tip height drive member is energized with a second electric control voltage whose amplitude increases as a function of time and which has a predetermined final value as a result of which the tip is lowered from the reference level to a defined depth into the surface, thus producing a pit having an accurately defined geometry, in that subsequently the tip is retracted to above the surface and the negative feedback control loop is switched on again so that the tip is first brought to its reference level before a subsequent pit is provided.
Claim 2
Independent Claim
249 words
A method of deforming a surface on a sub-micron scale by using a tip of a scanning tunneling microscope in which the drive means for moving the tip in a scanning direction parallel to the surface are used to cause the tip to describe a path in a plane parallel to the surface in accordance with the desired processing pattern in said surface, said tip, when describing said path, being held at a reference level at a constant distance from the surface by means of a first electric control voltage applied to a tip height drive member, said voltage being supplied by a negative feedback control loop which is controlled by a tunneling current between the tip and the surface, which current results from a constant tunneling voltage applied between the surface and the tip, characterized in that a surface deformation is brought about by interrupting the said negative feedback control loop, in that the tip height drive member is energized with a second electric control voltage whose amplitude increases as a function of time and which has a predetermined final value as a result of which the tip is lowered from the reference level to a defined depth into the surface, thus producing a pit having an accurately defined geometry, in that subsequently the tip is retracted to above the surface and the negative feedback control loop is switched on again so that the tip is first brought to its reference level before a subsequent pit is provided.
Claim 3
Dependent Claim
58 words
A method as claimed in Claim 1, characterized in that the second electric control voltage is obtained by summing the instantaneous value which the first control voltage has at the instant when the negative feedback control loop is interrupted and a third voltage whose amplitude increases as a function of time and which has a predetermined final value.
Claim 4
Dependent Claim
21 words
A method as claimed in Claim 1 or 2, characterized in that the pits are provided in a layer of silicon.
Claim 5
Dependent Claim
45 words
A method as claimed in Claim 1, 2 or 3, characterized in that a plurality of pits is provided in such a way that the mutual distance between their centres is smaller than the dimension of a pit in the scanning direction of the tip.
Claim 6
Dependent Claim
75 words
A method as claimed in Claim 1, 2 or 3 for inscribing information in a record carrier, characterized in that an electric signal representing the information to be inscribed is used for time-controlling the movement of the tip in the scanning direction and for determining the instants when the tip height control loop is interrupted or closed, respectively, and between which instants the said second control voltage is applied to the tip height drive member.
Claim 7
Dependent Claim
68 words
A record carrier provided with information areas arranged in tracks in which the information is encoded in the succession of the information areas in the track direction, which record carrier is inscribed by means of the method as claimed in Claim 5, characterized in that the information areas are pits in a surface, which pits have a uniform geometry with a surface area of less than 0.01 µm².
Claim 8
Dependent Claim
221 words
A device for performing the method as claimed in Claim 1, 2, 3, 4 or 5 which device comprises a holder for holding the material to be processed, a thin conducting stylus, a first and a second drive member for moving the stylus and the holder with respect to each other in two mutually perpendicular directions parallel to the plane of the holder, a tip height drive member for adjusting the distance between the tip and the surface and a negative feedback control loop for applying a first control voltage to the tip height drive member, characterized by an electronic circuit having an input for receiving an electric signal which comprises information about a pattern to be provided on the surface, said circuit having a first and a second output for supplying a first and a second control signal, which outputs are connected to the first and the second drive member, and a third output for supplying a signal during given time intervals for temporarily interrupting the tip height control loop, and by a voltage source which supplies a second control voltage for the tip height drive member during the said time intervals, the amplitude of said second control voltage increasing as a function of time to a predetermined final value which is larger than that of the first control voltage.
Claim 9
Dependent Claim
103 words
A device as claimed in Claim 7, characterized in that the tip height control loop has a sample and hold circuit a control input of which is connected to the third output of the electronic circuit, in that the output of the tip height control loop is connected to a first input of a summing device a second input of which is connected to a voltage source which is synchronously controlled with the sample and hold circuit and which supplies a voltage having an increasing amplitude, and in that the output of the summing device is connected to the tip height drive member.
Claim 10
Dependent Claim
79 words
An apparatus for inscribing and reading information in the form of a succession of information pits separated from one another in a record carrier surface, which apparatus is provided with a device as claimed fin Claim 7 or 8 for inscribing the information, characterized in that the read section of the apparatus is constituted by the said device in which the tip height drive member is controlled by only the said first control voltage or an information-independent control voltage.
References Cited (Backward Citations)
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