CN100545951C - Novel Microtip Area Array Device - Google Patents

Abstract

The invention relates to the technical field of scanning tunneling microscopes, in particular to a novel microtip surface array device. It consists of four parts: a clamping frame (1), a support membrane (2), a cantilever beam (3) and a microtip (7). The clamping frame (1) is used to clamp the entire device to combine with the external system and provide protection for the entire device structure; the support film (2) is used to support the cantilever beam structure, wires (4) and inner pads (5); The cantilever beam (3) units are sequentially tiled to form a planar array; the microtip (6) is formed by metal electroplating.

Description

Novel Microtip Area Array Device

technical field

The invention relates to the technical field of scanning tunneling microscopes, in particular to a novel microtip surface array device.

Background technique

Since the invention of the tunneling microscope (STM) by G. Bining et al. of IBM in 1982, the derived atomic force microscope (AFM) and scanning probe microscope (SPM) have been widely used in physics, chemistry, electronics, materials, medicine, etc. The field has been widely used and has become a powerful tool for people to study the microcosm. On this basis, various new types of cantilever beam micro-tip devices have emerged abroad, which have been applied to high-density data access, ultra-micro-machining of material surfaces, detection of material surfaces, sensors and many other aspects.

Existing patents: micro-tip linear device application number: 200510011987.8. Its structure is shown in Fig. 5, because the thickness of the clamping end (9) of the array microtip device of this structure is greater than the height of the microtip, that is, this device cannot freely process the surface of the material, and can only be processed within the reach of its cantilever beam. The edge of the material. Moreover, the cantilever beam of this structural device is completely exposed and easily damaged.

Compared with this structure, the surface array device introduced by the present invention has the advantages of higher efficiency, free processing of the material surface without border restrictions, and the protection of the cantilever beam by the clamping frame of the quartz glass material, which is not easy to be damaged.

Contents of the invention

The purpose of the present invention is to propose a metal microtip device supported by a surface array silicon nitride cantilever beam prepared based on a MEMS processing method. The purpose of this device is to maximize the efficiency of STM single probes in surface detection, material surface micro-nano processing, and high-density data access through "planar arraying", and at the same time solve the shortcomings of line array devices such as boundary limitations. . The number of area array units is the multiple of its improved efficiency.

Description of drawings

FIG. 1 is a schematic top view of the microtip surface array device of the present invention.

Fig. 2 is a schematic cross-sectional top view of the microtip surface array device of the present invention.

Fig. 3 is a schematic cross-sectional side view of the microtip surface array device of the present invention.

Fig. 4 is a schematic bottom view of the microtip surface array device of the present invention.

Fig. 5 is a diagram of a microtip linear device in the prior art.

Detailed ways

As shown in Figures 1, 2, 3, and 4, the device is generally composed of four parts: a clamping frame (1), a supporting film (2), a cantilever beam (3) and a microtip (6). Clamping frame (1), the material is quartz glass, the size is 3 cm x 2 cm, the thickness of the top wall is 0.3 cm, the thickness of the side wall is 0.5 cm, and there is a lead window of 0.5 cm x 1 cm on the top wall. This structure is used for clamping Holds the entire device to combine with external systems and provides protection for the entire device structure, having external pads (8) thereon. The outer pad (8) is composed of a gold film with a thickness of 3 mm x 1 mm and a thickness of 100 angstroms, and is used for connecting with peripheral circuits. The support film (2), with a thickness of 2 microns, is used to support the cantilever beam structure, wires (4) and inner pads (5). The wires on it are composed of a gold film with a width of 3 microns and a thickness of 100 angstroms, and are used to connect the cantilever beam (3) to the inner pad (5). The inner pad (5) is composed of a gold film with a thickness of 1 mm×1 mm and 100 angstroms, and the inner pad (5) and the outer pad (8) are connected through a gold wire (7) by a wire bonding process. The cantilever beam (3) is a hollow isosceles triangle with a height of 400 microns and a base of 100 microns, and the hollow part in the middle is an isosceles triangle with a height of 200 microns and a base of 50 microns. The micro-cantilever unit adopts sequential tiling form a planar array. Micro-tip area array device, the main body material is low stress silicon nitride with a thickness of 2 microns, and a gold film with a thickness of 100 angstroms is attached on it. The role of this gold film is to electrically connect the microtip to the inner pad, and it also forms a double-variant structure with silicon nitride. This structure is based on the large difference in the thermal expansion coefficient, and the microtip can be moved in the z-axis direction by changing the temperature of the cantilever beam when needed. The microtip (6) is produced by metal nickel electroplating, the size of the undercut surface is 5 microns×5 microns, the height is 7 microns, and the radius of curvature at the tip is less than 50 nanometers. Relying on the principle of tip discharge, when a small voltage (such as 5v) is applied between the pad and the material to be processed, a large electric field (about 10 ⁹ V/m, inversely proportional to the tip distance from the substrate), so that air ionization produces tunnel current. This kind of nickel tip can not only process and sense the surface of materials through tunnel current, but also can be heated by thermal resistance to process materials at high temperature, or directly use it for nanoimprinting.

Claims (8)

1. little tip surface array device; by holding frame (1); support membrane (2); (7) four parts in semi-girder (3) and little tip are formed; holding frame (1) is used for the clamping entire device to be made it to merge into the entire device structure with external system knot protection is provided; have outer pad (8) on it; outer pad (8) is used for linking to each other with peripheral circuit; support membrane (2) is used for supporting cantilever girder construction and lead (4) and interior pad (5); rely on lead key closing process to be connected between interior pad (5) and the outer pad (8) by gold thread (7); the mode that semi-girder (3) unit employing is tiled in proper order constitutes planar array, and little tip (6) are generated by metal plating.

2. according to little tip surface array device of claim 1, it is characterized in that, holding frame (1), material is a quartz glass, is of a size of the lead-in wire window that 1 centimetre of 0.5 cm x is arranged on 2 centimetres of 3 cm x, thick 0.3 centimetre of roof, 0.5 centimetre of side thickness, the roof.

3. according to little tip surface array device of claim 1, it is characterized in that outer pad (8) is made of 3 millimeters * 1 millimeter, the golden film of thick 100 dusts.

4. according to little tip surface array device of claim 1, it is characterized in that, support membrane (2), thick 2 microns, the lead on it is made of golden films wide 3 microns, thick 100 dusts, is used for semi-girder (3) is linked to each other with interior pad (5).

5. according to little tip surface array device of claim 1, it is characterized in that interior pad (5) is made of 1 millimeter * 1 millimeter, the golden film of thick 100 dusts.

6. according to little tip surface array device of claim 1, it is characterized in that semi-girder (3) is the hollow isosceles triangle on 100 microns on high 400 microns, base, intermediate hollow partly is high 200 microns, the isosceles triangle that the base is 50 microns.

7. according to little tip surface array device of claim 1, it is characterized in that, little tip surface array device, its material of main part is a low stress nitride silicon, thick 2 microns, adhere to golden film on it, thick 100 dusts, acting on of the golden film of this layer is connected little tip with interior pad electricity, it has constituted a kind of pair of variant structure with silicon nitride simultaneously.

8. according to little tip surface array device of claim 1, it is characterized in that little tip (6) electroplate generation by metallic nickel, 5 microns * 5 microns of undercut surfaces sizes, high 7 microns, its most advanced and sophisticated place radius-of-curvature is less than 50 nanometers.

Images