Radio frequency identification device implemented with a metal-gate semiconductor fabrication process

• US 7,191,953 B2
• Filed: 06/01/2005
• Issued: 03/20/2007
• Est. Priority Date: 06/01/2004
• Status: Expired due to Fees

• Current Assignee: G-Time Electronic Company Limited
• Original Assignee: G-Time Electronic Company Limited
• Inventors: Wu, Che Ming, Wu, Ying Feng, Lee, Wen Feng
• Primary Examiner(s): LEE, SEUNG H
• Application Number:
  US11/140,901
• Publication Number:
  US 20050263603A1
• Time in Patent Office: 657 Days
• Field of Search: 235/436, 235/476, 235/451, 340/825
• US Class Current: 235/492
• CPC Class Codes: G06K 19/0701 at least one of the integrated circuit chips comprising an arrangement for power management
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 19/07735 the record carrier comprising means for protecting against electrostatic discharge

Abstract

The present invention discloses a radio frequency identification device implemented with a metal-gate semiconductor fabrication process, wherein the charge capacitor, which is formed by the special parasitic N-type and P-type guard rings in the chip fabricated with the metal-gate process, incorporated with the original P-type and N-type transistors of metal oxide semiconductor (PMOS/NMOS) not only can provide a horizontal surface current but also can provide a rectified current for the performance of the entire circuit, which can advance the metal gate process to RFID industry in cooperation with an identification code holder circuit and a non-synchronous local oscillation circuit so that the fabrication cost can be lowered and the fabrication time can be shortened.

Claims

1. A radio frequency identification device implemented with a metal-gate semiconductor fabrication process, comprising:

a resonance circuit, stabilizing frequencies and selecting radio frequencies;

a charge capacitor, formed by parasitic junction capacitors created by N-type doped and P-type doped guard rings formed in the metal-gate process;

a rectification circuit, coupled to said resonance circuit and parallel-connected with said charge capacitor, and cooperating with said resonance circuit and said charge capacitor to provide an operational power for entire said device;

at least one identification code holder circuit, separately coupled to bonding pads, wherein each said bonding pad stores an identification code and said identification code holder circuit utilizes an initial state to control said bonding pad;

a non-synchronous local oscillation circuit, generating a local oscillation signal; and

a digital control/logic circuit, utilizing said local oscillation signal to control a modulator according to said identification codes inside said bonding pads in order to generate a radio frequency identification signal.

2. The radio frequency identification device implemented with a metal-gate semiconductor fabrication process according to claim 1, further comprising:

an over-voltage protection circuit and an low-voltage reset circuit, separately connected with said charge capacitor, wherein said over-voltage protection circuit is to avoid too high a voltage of said operational power, and said low-voltage reset circuit is to detect too low a voltage of said operational power and generate a reset signal in order to avoid a malfunction resulting from too low an induced voltage.

3. The radio frequency identification device implemented with a metal-gate semiconductor fabrication process according to claim 2, wherein said over-voltage protection circuit or said reset circuit is formed via coupling a set of resistances and a diode to a set of amplifiers, and the P-type doped end of said diode is connected to the positive voltage of the device, which enables the parasitic bipolar diode thereof not to conduct.

4. The radio frequency identification device implemented with a metal-gate semiconductor fabrication process according to claim 1, wherein said resonance circuit is formed of an antenna and an internal capacitor.

5. The radio frequency identification device implemented with a metal-gate semiconductor fabrication process according to claim 1, wherein cooperating with said non-synchronous local oscillation circuit, a program code is further installed inside a radio-frequency identification reader in order to correctly read data.