Methods utilizing scanning probe microscope tips and products thereof or produced thereby
The invention provides a lithographic method referred to as “dip pen” nanolithography (DPN). DPN utilizes a scanning probe microscope (SPM) tip (e.g., an atomic force microscope (AFM) tip) as a “pen,” a solid-state substrate (e.g., gold) as “paper,” and molecules with a chemical affinity for the solid-state substrate as “ink.” Capillary transport of molecules from the SPM tip to the solid substrate is used in DPN to directly write patterns consisting of a relatively small collection of molecules in submicrometer dimensions, making DPN useful in the fabrication of a variety of microscale and nanoscale devices. The invention also provides substrates patterned by DPN, including submicrometer combinatorial arrays, and kits, devices and software for performing DPN. The invention further provides a method of performing AFM imaging in air. The method comprises coating an AFM tip with a hydrophobic compound, the hydrophobic compound being selected so that AFM imaging performed using the coated AFM tip is improved compared to AFM imaging performed using an uncoated AFM tip. Finally, the invention provides AFM tips coated with the hydrophobic compounds.
1. An atomic force microscope adapted for performing nanolithography comprising:
a sample holder adapted for receiving and holding a substrate; and
at least one well adapted for holding a patterning compound which does not cover the substrate when the substrate is placed in the sample holder so that the patterning compound can be transferred from the well to the substrate by a tip disposed on a cantilever,
the well being positioned so that the well will be adjacent the substrate when the substrate is placed in the sample holder,
wherein the atomic force microscope further comprises an isolation chamber for control of relative humidity during the performance of the nanolithography.
2. The microscope of claim 1 comprising a plurality of wells, at least one well holding a patterning compound, the other well(s) holding a patterning compound or a rinsing solvent, the wells being positioned so that they will be adjacent the substrate when the substrate is placed in the sample holder.
3. The atomic force microscope adapted for performing nanolithography according to claim 1 further comprising: a plurality of scanning probe microscope tips; and a tilt stage adapted for receiving and holding the sample holder, the sample holder being adapted for receiving and holding the substrate.
4. The microscope of claim 3 wherein the plurality of scanning probe microscope tips comprises an imaging tip and at least one writing tip.
5. The microscope of claim 3 wherein at least one of the tips is coated with a patterning compound.
6. The microscope of claim 5 further comprising a substrate in the sample holder and wherein at least one of tips is contacted with the substrate so that the patterning compound coated on the tip is applied to the substrate so as to produce a desired pattern.
7. The microscope of claim 6 wherein the tilt stage is adjusted so that all of the tips are contacted with the substrate simultaneously and each of them produces the same pattern.
8. The microscope of claim 7 wherein the plurality of scanning probe microscope tips comprises an imaging tip and at least one writing tip, and each writing tip produces the same pattern as the imaging tip.
9. The microscope of claim 6 wherein the tilt stage is adjusted so that each of the plurality of tips is contacted separately with the substrate so that each tip produces a separate desired pattern.
10. The microscope of claim 3 , wherein the tips are atomic force microscope tips.
11. An instrument comprising:
a scanner adapted for (i) contacting a scanning probe microscope tip on a cantilever with a patterning compound in a well to coat the tip with patterning compound; (ii) transferring the patterning compound from the tip to a substrate surface;
a sample holder adapted for receiving and holding the substrate; and
at least one well adapted for holding the patterning compound which does not cover the substrate when the substrate is placed in the sample holder so that the patterning compound can be transferred from the well to the substrate by a tip,
the well being positioned so that the well will be adjacent the substrate when the substrate is placed in the sample holder,
wherein the instrument further comprises an isolation chamber for control of relative humidity during the transferring.
12. The instrument of claim 11 , wherein the scanning probe microscope tip is an atomic force microscope tip.
13. The instrument of claim 11 , wherein the scanning probe microscope tip on a cantilever is part of an array of a plurality of scanning probe microscope tips on cantilevers.
14. An atomic force microscope adapted for performing nanolithography comprising:
a sample holder adapted for receiving and holding a substrate; and
at least one well adapted for holding a patterning compound which does not cover the substrate when the substrate is placed in the sample holder so that the patterning compound can be transferred from the well to the substrate by a tip disposed on a cantilever,
the well being positioned so that the well will be adjacent the substrate when the substrate is placed in the sample holders,
wherein the atomic force microscope further comprises a device adapted for control of relative humidity during the performance of the nanolithography.