Polishing pad and polishing device   

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention is related to a polishing pad, and particularly to a polishing pad with a pressure sensor and the polishing apparatus thereof.

2. Description of Related Art

Most of electric chips are consisted of various laminated layers with various materials. For example, semiconductor wafer (silicon wafer) is one of the various materials. For polarization or other destination, a polishing process or thinning process is necessary for the removal of excess laminated material when a new laminated layer is intended to be added. Such a polishing process is called chemical mechanical polishing (CMP). Many CMP steps may be necessary for the requirement of uniform surface for the addition of laminated layers.

However, with the advances of manufacture technology, the higher density the layout of conductive lines is, the more narrow the width of the conductive lines is. Thus, the tolerance of pressure error reduces because the pressure supplied by the polishing apparatus is only 1 PSI to 2 PSI. The pressure setting is one of important issues for the polishing process. Moreover, a polishing pad is generally sandwiched between the polishing apparatus and the concerned work piece. Thus, there is pressure bias between the preset pressure and an actual pressure.

Accordingly, the present invention provides a polishing pad with a pressure sensor and a polishing apparatus thereof. The pressure sensor is advantageous positioned to prevent the pressure sensor from being interfered and abraded by polishing chemicals. The pressure sensor directly detects the pressure loaded on a concerned work piece by the polishing apparatus and positively or passively transmits the pressure signal back. Thus, the drawbacks of over pressure or non-uniform distribution of pressure may be reduced to further the yield of the concerned polished work piece.

SUMMARY

Accordingly, the present invention provides a polishing pad with a pressure sensor. The polishing pad is used in the polishing process of semiconductor and other work piece, which includes at least one substrate, at least one pressure sensor and at least one signal transmitting module. The substrate has a polishing face, a bottom face opposite to the polishing face, and at least one cavity set on the bottom face of the substrate. The pressure sensor is set in the cavity and configured for providing a pressure signal. The signal transmitting module is set on the polishing pad and configured for transmitting a pressure signal. The pressure signal is a loading pressure value and/or loading pressure distribution on the polishing pad with a preset range. Thus, with the pressure signal, the polishing apparatus prevents the concerned work piece from being over polished to further improve polishing quality and yield.

One of objects of the present invention provides a polishing pad with a pressure sensor to detect pressure value and distribution during polishing process.

One of objects of the present invention provides a polishing pad with a pressure sensor to prevent a concerned work piece from over polishing and improve polishing quality and yield.

One of objects of the present invention provides a polishing pad with a pressure sensor to implement a preferred method of signal transmission and signal transmission in time.

The invention as well as a preferred mode of use, further objectives and advantages thereof will best be understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a cross-sectional schematic diagram illustrating a polishing pad in accordance with one preferred embodiment of the present invention.

FIG. 2 is a cross-sectional schematic diagram illustrating a polishing pad in accordance with one preferred embodiment of the present invention.

FIG. 3 is a cross-sectional schematic diagram illustrating a signal transmitting module in according with one preferred embodiment of the present invention.

FIG. 4 is a cross-sectional schematic diagram illustrating another signal transmitting module in according with one preferred embodiment of the present invention.

FIG. 5 is a cross-sectional schematic diagram illustrating another signal transmitting module in according with one preferred embodiment of the present invention.

FIG. 6 is a cross-sectional schematic diagram illustrating another signal transmitting module in according with one preferred embodiment of the present invention.

FIG. 7 is a cross-sectional schematic diagram illustrating a polishing apparatus in according with one preferred embodiment of the present invention.

DETAILED DESCRIPTION

The present invention provides a polishing pad with a sensor. Some sensors or the detail process or manufacture of the polishing pad used are implemented by the current technology. Thus, some known description is not mentioned in following illustration. The sizes of components are not practical rather than for illustration.

FIG. 1 is a cross-sectional schematic diagram illustrating a polishing pad in accordance with one preferred embodiment of the present invention. The polishing pad 2 is used in the polishing process of semiconductor and other work piece, which includes at least one substrate 21, at least one pressure sensor 3 and at least one signal transmitting module (not shown in the figure). The substrate 21 has a polishing face 211, a bottom face 212 opposite to the polishing face 211, and at least one cavity 213 set on the bottom face 212 of the substrate 21. The pressure sensor 3 is set in the cavity 213 and configured for providing a pressure signal. The signal transmitting module is set on the polishing pad 2 and configured for transmitting a pressure signal. In one embodiment, the pressure signal is a loading pressure value and/or loading pressure distribution on the polishing pad 2 with a preset range. Thus, with the pressure signal, the polishing apparatus prevents the concerned work piece from being over polished to further improve polishing quality and yield. Next, in FIG. 2, the polishing pad 2 have more than the two substrates 21 and the pressure sensor 3 is sandwiched between the two substrates 21 to form a complex polishing pad.

FIG. 3 is a cross-sectional schematic diagram illustrating a signal transmitting module in according with one preferred embodiment of the present invention. The exemplary signal transmitting module includes a printed circuit board 31 (PCB) and couples a circuit 311 as a power supply for direct transmission.

FIG. 4 is a cross-sectional schematic diagram illustrating another signal transmitting module in according with one preferred embodiment of the present invention. The exemplary signal transmitting module includes at least one conductive line 32 as the power supply to positively transmit signal.

FIG. 5 is a cross-sectional schematic diagram illustrating another signal transmitting module in according with one preferred embodiment of the present invention. The exemplary signal transmitting module includes at least one battery of power supply 33 which may be button battery, Mercury battery, dry battery, alkaline battery, Lead/Acid Battery, Nickel-Cadmium Battery, Nickel-Metal hydride batteries, Secondary lithium battery, Li-ion Battery, polymer lithium battery, fuel battery and solar battery and used to positively transmit the signal.

FIG. 6 is a cross-sectional schematic diagram illustrating another signal transmitting module in according with one preferred embodiment of the present invention. The exemplary signal transmitting module includes at least one wireless signal emitter 34 to passively transmit the signal.

Another signal transmitting module in according with one preferred embodiment of the present invention is provided herein. The exemplary signal transmitting module is integrated with the pressure sensor 3 into a whole device (not shown in the figure). The whole device includes a chip, a controller, a wireless signal emitter and at least one a power supply. The frequency range of the wireless signal emitter is about from 100 MHz to 3 GHz. Furthermore, the power supply may be a vibrating motor device, external magnetic field motor device, or button battery, Mercury battery, dry battery, alkaline battery, Lead/Acid Battery, Nickel-Cadmium Battery, Nickel-Metal hydride batteries, Secondary lithium battery, Li-ion Battery, polymer lithium battery, fuel battery and solar battery, and so on. These configuration is a passive method of transmitting signal.

FIG. 7 is a cross-sectional schematic diagram illustrating a polishing apparatus in according with one preferred embodiment of the present invention. The polishing apparatus 4 is configured for polishing a work piece 5 and loading a polishing pad 2. The polishing pad 2 includes at least one substrate 21, at least one pressure sensor 3 and at least one first signal transmitting module (not shown in the figure). The substrate 21 includes a polishing face 211, a bottom face 212 opposite to the polishing face 211 and a cavity 213 set on the bottom face 212 of the substrate 21. The pressure sensor 3 is set in the cavity 213 and configured for providing a pressure signal. The first signal transmitting module is set on the polishing pad 2 and configured for transmitting the pressure signal. In one embodiment, the pressure signal is a loading pressure value and/or loading pressure distribution on the polishing pad 2 with a preset range. An alarm device 47 is configured for emitting an alarm signal on condition of the pressure signal out of the present range to stop the polishing apparatus 4.

Furthermore, the polishing apparatus 4 includes a first platform 41, a driving device 411, a second platform 42, a pressing device 43, at least one signal receiving module 44 and a display device 45. The polishing pad 2 is sealed with an adhesive 46 and fixed on the first platform 41. The adhesive 46 may be a pressure-sensitive adhesive. The first platform 41 is configured for loading the polishing pad 2 and coupling the bottom face 212 of the polishing pad 2. In one embodiment, the driving device 411 drives the first platform 41 to rotate. The second platform 42 is configured for loading the work piece 5. The pressing device 43 is configured for providing a pressure loaded between the polishing pad 2 of the first platform 41 and the work piece 5 of the second platform 42. The signal receiving module 44 is configured for receiving the pressure signal provided by the polishing pad 2. The signal receiving module 44 may be a wireless signal receiver 441. The display device 45 is configured for displaying the pressure signal.

Accordingly, a second signal transmitting module is configured for coupling with the first signal transmitting module of the polishing pad 2 and the signal receiving module 44 of the polishing apparatus 4. The second signal transmitting module may be a print circuit board (PCB) 31, a conductive line 32 or a connector. In one embodiment, the second signal transmitting module is set on a surface of the polishing pad 2 attached to the first platform 41.

Accordingly, the present invention provides a polishing pad with a pressure sensor and a polishing apparatus thereof. The pressure sensor is advantageous positioned to prevent the pressure sensor from being interfered and abraded by polishing chemicals. The pressure sensor directly detects the pressure loaded on a concerned work piece by the polishing apparatus and positively or passively transmits the pressure signal back. Thus, the drawbacks of over pressure or non-uniform distribution of pressure may be reduced to further the yield of the concerned polished work piece.

Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that other modifications and variation can be made without departing the spirit and scope of the invention as hereafter claimed.