RFID silicon antenna

• US 20080217560A1
• Filed: 03/07/2007
• Published: 09/11/2008
• Est. Priority Date: 03/07/2007
• Status: Active Grant

• Current Assignee: James Neil Rodgers
• Original Assignee: James Neil Rodgers
• Inventors: Rodgers, James Neil
• Granted Patent: US 7,681,301 B2
• Time in Patent Office: Days
• US Class Current: 250/492.2
• CPC Class Codes: B23K 2101/40 Semiconductor devices
• CPC Class Codes: B23K 26/0624 using ultrashort pulses, i.e. pulses of 1ns or less
• CPC Class Codes: B23K 26/3584 Increasing rugosity, e.g. roughening
• CPC Class Codes: Y10T 29/49016 Antenna or wave energy "plumbing" making
• CPC Class Codes: Y10T 29/49018 with other electrical component

Abstract

The system of producing an RFID antenna using the silicon in an integrated circuit as the resonant antenna material for the purpose of reducing the cost of an RFID system and for the purpose of increasing the range and selectivity of the RFID system. According to this invention the base silicon sheets which make up the primary building material of the silicon chip (integrated circuit) is subjected to a laser ablation process. This creates three dimensional nano structures on the surface of the silicon thereby raising its absorption rate of electro magnetic signals. On the reverse side of the same silicon sheet a directional antenna is etched using standard photographic reduction techniques and standard semi conductor industry manufacturing methods. The two sides of the silicon are connected through doping aluminum or copper impurities into these same base silicon sheets causing conductivity within the sheet of silicon.

Claims

1. ) A system of using a generic laser pulse device to treat commercially produced bulk sheets of silicon wafer base material with a pulse of sharply focused laser energy;

a system of using the bulk commercially produced sheets of silicon wafers so that they are manufactured into radio frequency identification antennas after the femtosecond laser ablation technique has been applied;

all for the purpose of creating three dimensional nano structures on the silicon base material in order to increase radioactive sensitivity to electro magnetic signals.

3. ) A system of claim 1 whereby the femtosecond laser ablation is limited to the silicon base material which is a part of the silicon layering process involved in manufacturing an integrated circuit which silicon base material is so treated to be incorporated into one of the elements of a radio frequency identification resonant antenna harvesting system.

4. ) A system of claim 1 whereby the generic laser pulse device used to treat commercially produced bulk sheets of the silicon base material is of the Ti:

Sapphire Femto-Second laser type used for machining silicon surfaces for the purpose of increasing the radiation sensitivity of the silicon base material used in the construction of an RFID antenna designed to increase the gain and range of the resonant antenna.

5. ) The system of claim 1 whereby the laser ablation process alters the surface of the silicon base material creating surface roughness and enables the formation of micro and nano sized structures for the purpose of increasing the electro magnetic absorption rate of the silicon base material used in the construction of an RFID antenna to increase the gain and range of same while, at the same time, reducing the cost.

6. ) The system of claim 1 whereby reflectance measurements are made of the silicon base material subsequent to the laser ablation process through the use of ellipsometry and integrating sphere as well as the EDX, XPS, and AES techniques which are used to analyze the surface properties of the metal base material to determine the parameters of the reflectance values of the laser machined silicon base material for the purpose of verifying the presence of sufficient three dimensional nano structures to adequately increase the radioactive sensitivity of the antenna.

7. ) The system of claim 1 whereby the femtosecond laser pulses of high intensity light are less than a picosecond but long enough duration in femotoseconds to reach the ablation threshold yet short enough to confine collateral damage on the base silicon material to less than 10 nano meters to ensure the structural integrity of the silicon base material;

8. ) The system of claim 1 whereby the femtosecond laser pulses emanate from technologies of the nonlinear multi photon laser matter interaction processes thereby allowing the ablation process to overcome the diffraction limit for the purpose of fabricating three dimensional nano structures on the base silicon materials to increase electro magnetic signal sensitivity.

9. ) The system of claim 1 whereby the femtosecond laser pulse is unleashed at a frequency which equals the frequency of surface charge oscillations on the base silicon material thereby increasing absorption of the laser pulse.

10. ) The system of claim 1 whereby the femtosecond laser ablation can be applied at a sufficiently high fluence and with a multitude of applied pulses for the purpose of raising the absorption rate incrementally from 50% to 100% on the base silicon materials;

11. ) The system of claim 1 whereby the three dimensional nano structures are developed from a process of a nano scale melt which relocates the base silicon material from the center of the melted site to peripheral areas resulting in nano cavities, nano rims, and nano protrusions for the purpose of raising the electro magnetic signal absorption rate on the base silicon materials.

15. ) The system of claim 2 whereby the master stencil mask is applied to the reverse side of base silicon building material outlined in claim 1.

16. ) The system of claim 1 and 2 whereby the master stencil mask and three dimension nano particles which are manufactured into either side of one sheet of bulk commercial silicon wafer base material are cut using normal semiconductor industry methods into individual wafers.

17. ) The system of claim 1 and 2 whereby the individual wafers are applied using the standard semiconductor industry layering method onto a semiconductor to be used in an RFID system.

2. ) A system of manufacturing a system resonant RFID antenna using existing semi conductor industry best practices;

a system of designing a complex resonant antenna at a macro level and reducing it through the process of de-magnification to nano size;

a system to form this structure on the reverse side of silicon wafers treated with laser ablation;

all for the purpose of increasing the radioactive sensitivity of the RFID antenna and to increase the gain and range of same.

12. ) The system of claim 2 whereby an optimally functional RFID antenna is designed at a macro level to be a resonant match to the RFID system for which it is planned for use for the purpose of cutting this macro level template antenna to general direction and the specific resonant frequency of the host RFID system.

13. ) The system of claim 2 whereby the details of the macro level template antenna design are photo exposed to a thin layer of photosensitive polymer which is part of the surface of a polished silicon wafer.

14. ) The system of claim 2 whereby the details of design are demagnified or reduced photographically to an image which perfectly replicates the design features of the macro level template directional antenna on a master stencil mask.