JPH0864558A - Method of manufacturing micro electronic mechanical type device - Google Patents

Abstract

PURPOSE: To execute all manufacture processes and test processes not in the state of device but in the state of wafer. CONSTITUTION: A wafer 20 is attached inside a saw frame 24 on a dicing tape 22, and the individual devices are generally separated by sawing before completing device manufacture. The devices are left on the dicing tape during the other manufacture processes. In a certain manufacture process, it is required to coat the adhesive material of the dicing tape with a protective cover. After completing all the manufacture processes, including the application of protective overcoat and a function test, the device is removed from the dicing tape and packaged.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to the field of integrated circuit processing technology, and more particularly to a method of making microelectromechanical devices including deformable micromirror devices.

[0002]

BACKGROUND OF THE INVENTION In order to make integrated circuit (IC) processing cost-effective, individual circuits or devices are generally mass-produced using semiconductor wafers, such that many devices are manufactured simultaneously on one substrate. Has been done. A typical process flow for integrated circuits follows the steps of manufacturing the device, then testing the device, isolating the device, and packaging the device. When the device is separated from the wafer, dicing chips are created that consist of the particles and powder of the wafer. This dicing debris is washed off the surface of the IC prior to bonding the device to the package.

[0003]

Microelectromechanical systems (MEMS) or micromechanical devices must undergo and withstand some of the standard IC manufacturing processes such as device isolation and cleaning. , Often have structures that are overly fragile. Some ME
MS, eg digital micromirror device (DM
Due to D) and the fragile nature of some accelerometers, standard IC process steps must be rearranged to prevent the finished device from being destroyed. D
The MD is described in US Pat. No. 5,061,049, entitled "Spatial Light Modulator and Method," assigned to Texas Instruments Incorporated. Accelerometer
US Patent Application No. 07 entitled "Digital Accelerometer", assigned to Texas Instruments, Inc.
/ 883,616. As described in the above patents, these MEMS have microstructures suspended over an air gap above electrodes formed on the surface of a silicon substrate. Forming these structures,
Etching away sacrificial material from the air gap makes these devices extremely fragile. These devices are inaccessible to liquids such as those that occur during the wafer cleaning process without fear of breaking the mirror.
Therefore, these devices must be cut and the dicing debris cleaned prior to etching the sacrificial material from the underlying mirror.

Separating the wafer before completing the device results in handling a wide range of devices during the rest of the device manufacturing process, such as passivation and device testing. Performing these processes at the wafer state, unlike the device state, significantly reduces the handling required. The reason is that the processing equipment only needs to move and align one wafer instead of multiple devices. Die tests
Precise alignment is extremely important for towing).

The present invention discloses a method by which wafer processing techniques can be used to complete the entire device manufacturing and test process.

[0006]

In a method of manufacturing a microelectromechanical device or an integrated circuit device,
Mount the partially completed device wafer on dicing tape in a saw frame. The devices are separated by either sawing the wafer or other wafer separation techniques.
Complete device fabrication before removing the device from the dicing tape. In some applications it may be advantageous to cover the exposed adhesive of the dicing tape with a protective cover. The advantage of this method is that the device can be fully processed using efficient industry standard wafer handling techniques.

[0007]

DETAILED DESCRIPTION OF THE INVENTION The method and protective cover disclosed herein are for devices manufactured as microelectromechanical devices having a particularly fragile structure in the wafer, avoiding the use of conventional wafer manufacturing process flows. Applicable to manufacturing. For purposes of illustration, the invention will be described by way of example with reference to the fabrication of digital micromirror devices and accelerometers. The specific embodiments are merely illustrative of possible configurations of the invention and are not intended to limit the invention to the manufacture of DMDs or accelerometers only. The methods disclosed herein can be used with any type of integrated circuit or microelectromechanical device.

A typical DMD device structure is shown in FIGS. 1A-1C. The elements shown are not to scale for all of the drawings included in this disclosure. In most cases, wafer and device layer thicknesses are greatly exaggerated for purposes of illustration. The DMD generally consists of an array of elements 50. Each DMD element 50 typically includes two torsion hinges (torsi) on a silicon substrate 56.
metal beam 5 suspended by an on hinge 54
It consists of two. An insulating oxide layer 58 is grown on the silicon substrate 56, and addressing electrodes 60, 62, 6 are formed on the oxide layer 58.
4 and landing electrodes 66, 68 are deposited. A planarizing (planarizing) spacer layer 68, sometimes referred to as a sacrificial layer, is formed on the substrate, and a hinge metal layer 70 is deposited on the spacer layer 68 followed by a beam metal layer 72. Etching the metal layer to form the beam 52 and hinge 54 of each element 50

In a typical process flow for DMD fabrication, the devices must be separated by usually sawing between rows of devices on the wafer before undercutting the mirror. Spacer layer 6 below beam 52 and hinge 54 after device isolation
8 is etched away to allow the beam to twist on the hinge as shown in FIG. 1C. This undercut operation is usually performed in the plasma reactor. Access holes 74 and gaps 76 allow the plasma to etch away spacer material 68 below beam 52 and hinges 54. After etching away the spacer layer 68, the device is made chemically less reactive by a process called passivation.

A similar process flow is used to manufacture some accelerometers. 2A and 2B show an array of cantilever accelerometers 78. Beam 8 for each accelerometer
4 comprises a precision mass called a proof mass 80 supported by a hinge 82 attached to the 4. Below each accelerometer is a contact 86, which is deposited on a silicon substrate 88 covered by an insulating oxide layer 90. Planarized spacer layer 92 separates beam 84 and electrode 86. After removing the spacer layer from below the proof mass 80 and the hinge 82 by etching, the proof mass 80 is sufficiently accelerated.
Can be deflected to contact the contact 86.

Spacer layer 68 or 92 as described above
Once etched away, the device becomes extremely brittle and cannot contact the liquid without destroying it, for example during the wafer cleaning process. Since the finished devices are non-cleanable, they are typically separated by sawing before being etched away from the spacer layer. After being separated by sawing, these devices are handled separately during the undercut, die test and protective overcoat processes.

The present invention allows for centralized processing of all devices from a single wafer during the manufacturing process. According to one embodiment of the illustrated invention shown in FIGS. 3A and 3B, a silicon wafer 20 containing a partially completed microelectromechanical device is bonded to a bonding side 21 of a dicing tape 22 held on a saw frame 24. Attached to. FIG. 3B is a sectional view of the wafer 20 on the dicing tape 22 in the saw frame 24.

Wafer 20 is typically silicon,
Other materials such as quartz or gallium arsenide can also be used. To prevent the wafer from being destroyed during the sawing operation, a temporary protective coating can be applied to the surface of the wafer 20 prior to attachment to the wafer in the saw frame. The saw frame is optionally attached so that the devices can be separated by sawing. The saw cuts completely through the wafer and into the dicing tape. However, the dicing tape is not completely cut. For example,
If the thickness of the dicing tape is about 0.1 mm (4 mil), only about 0.025 mm (1 mil) of it will be cut.

After separating the wafer by sawing,
Particles generated during the sawing operation are generally cleaned from the wafer, dicing tape and sawing frame. Once the temporary protective coating has been applied to the wafer, the sawframe can be attached by a centrifuge and the wafer sprayed with solvent to remove the protective coating. 4A and 4B show saw wafer 24 and saw frame 24 attached to centrifuge 28. The dimensions and placement of the device shown in FIG. 4A are for illustration only. Individual devices are shown in FIG. 4B for clarity. Once installed in the centrifuge, the surface of the wafer is sprayed with solvent to remove the protective coating. The centrifuge spins off the solvent and the dissolved coating from the wafer.

Another method of removing the temporary protective coating in the centrifuge is to install a saw frame in the spray generating hood. FIG. 5 shows the saw frame 24 and wafer 26 mounted within the spray generating hood 30. The solvent 32 is sprayed from the spray nozzle 34 onto the surface of the sawed wafer 26 in a state where the solvent 32 is positioned inside the spray generation hood. Solvent gas 36 is removed through a vent 38 at the rear of the hood. The solvent and particles 40 exit the hood through a drain 42 provided at the bottom of the hood.

After removing the protective coating from the wafer, some of the spacer layer 68 or 92 must be removed to leave the mirror or accelerometer support beam. This undercut operation is generally performed in a plasma reactor. Adhesive 2 on dicing tape 22
A protective cover can be placed on the exposed adhesive 21 of the dicing tape 22 in order to prevent contact with the plasma on the substrate 1. 6A and 6B show sawed wafer 26 with protective cover 44 attached to saw frame 24 provided on exposed adhesive 21 of dicing tape 22. For simplicity, the individual devices are not shown in Figure 6B. The protective cover 44 can be made of a material that can withstand exposure to the plasma reactor. For example, the cover can be in the form of a ceramic ring or donut attached to dicing tape. Another method is to use another portion of the dicing tape that is cut to the proper shape and attached so that the adhesive surfaces of the protective cover 44 and the dicing tape used as the dicing tape 22 are mated. The protective cover may be quartz or metal or other material capable of withstanding a plasma etching environment. The sawframe with the sawed wafer and protective cover attached uses a plasma etching process to undercut the mirror or accelerometer beam while retaining the susceptor designed to hold the sawframe.
can be installed on the plate. FIG. 7 shows a susceptor plate 4 with a recessed area 48 adapted to hold the saw frame 24 during the plasma etching process.
6 is shown.

After the undercutting operation, the device can be passivated and electrically and optically tested while still attached to the saw frame. Testing must be greatly simplified because the wafer is still intact in nature because the individual devices 24 must be aligned with each other. Therefore, as shown in FIG. 8, the probe card 49 of the multi-prober is used to align each device 2 with the sawed wafer.
It must be able to match 7 exactly. Movement of the devices on the dicing tape allows each device to be aligned separately using a visually assisted multi-prober.

After testing the device, the device can be removed from the dicing tape and the saw frame and wafer can be mounted on a pick and place machine so that the device rests on the lead frame for the package assembly process. The device removal process of the improved process flow taught by the present invention is a standard IC
Must be identical to the device removal process. Therefore, no changes are required to the device removal and packaging assembly process.

Thus, prior to completing the fabrication of the device, a particular embodiment for a microelectromechanical device for separating the device from the wafer has been described, and such a particular reference is set forth in the following claims. It should not be considered as limiting the scope of the invention, except as noted. Although the invention has been described with reference to certain specific embodiments, further modifications will occur to those skilled in the art and are considered to be covered by the appended claims. Should be.

Regarding the above description, the following items will be disclosed. (1) Providing a part of the dicing tape having an adhesive surface,
Attaching a wafer containing a partially manufactured device to the adhesive surface of the dicing tape, subdividing the wafer, separating the partially manufactured device and leaving it mounted on the dicing tape, A method for producing a microelectromechanical device, which comprises the steps of continuously producing separated devices and removing the device from the dicing tape. (2) The method according to claim 1, further comprising the step of placing a protective cover on the exposed portion of the adhesive surface of the dicing tape. (3) The method according to claim 2, wherein the protective cover is selected from the group consisting of ceramic, metal, quartz and dicing tape. (4) The method of claim 1, further comprising applying a temporary protective coating to the device prior to the subdividing step. (5) The method of claim 4, further comprising the step of removing the temporary protective coating from the device. (6) The method according to item 1, wherein the device is a digital micromirror device (DMD). (7) The method according to item 1, wherein the device is an accelerometer. (8) The method of claim 1, wherein the continuing manufacturing step includes plasma etching the device. (9) The method according to item 1, wherein the subsequent manufacturing step includes passivating the device. (10) The method of claim 1, wherein the continuing manufacturing step includes testing the device.

(11) A part of a dicing tape having an adhesive surface is provided, a wafer containing a partially manufactured digital micromirror device is attached to the adhesive surface of the dicing tape, the wafer is subdivided, and the part is formed. Separately manufactured digital micromirror device is separated and left mounted on the dicing tape,
A protective cover selected from the group consisting of ceramic, metal, quartz and dicing tape is placed on the exposed portion of the adhesive surface of the dicing tape, and the manufacturing of the separated digital micromirror device is continued. A method of manufacturing a digital micromirror device including steps of removing a mirror device. (12) The method according to claim 11, wherein the continuing manufacturing step includes plasma etching the digital micromirror device. (13) The method according to item 11, wherein the continuing manufacturing step includes passivating the digital micromirror device. (14) The method according to item 11, wherein the continuing manufacturing step includes testing the digital micromirror device. (15) The method of claim 11, further comprising applying a temporary protective coating to the digital micromirror device before the sub-dividing step. 16. The method of claim 15, further comprising the step of removing the temporary protective coating from the digital micromirror device.

(17) A part of a dicing tape having an adhesive surface is provided, a wafer including a partially manufactured accelerometer is attached to the adhesive surface of the dicing tape, the wafer is subdivided, and the partially The manufactured accelerometer is separated and left mounted on the dicing tape, and a protective cover selected from the group consisting of ceramic, metal, quartz and dicing tape is placed on the exposed portion of the adhesive surface of the dicing tape, A method of manufacturing an accelerometer, which comprises the steps of continuing to manufacture the separated accelerometer and removing the accelerometer from the dicing tape. (18) The method of claim 17, wherein the continuing manufacturing step includes plasma etching the accelerometer. (19) The method of claim 17, wherein the continuing manufacturing step includes passivating the accelerometer. (20) The method of claim 17, wherein the continuing manufacturing step includes testing the accelerometer.

(21) A method for processing a wafer containing microelectromechanical devices that allows all manufacturing and testing steps to be performed in the wafer state rather than the device state. Dicing tape 22
The wafer 20 is mounted in the upper saw frame 24 and the individual devices 27 are separated, typically by sawing, before device fabrication is complete. These devices are left on the dicing tape during other manufacturing steps. In some manufacturing processes it is necessary to cover the adhesive of the dicing tape with a protective cover 44. After completing all manufacturing steps, including applying protective overcoat and functional testing, remove the device from the dicing tape and package.

[Brief description of drawings]

FIG. 1A is a perspective view of one element of a digital micromirror device. 1B is a cross-sectional view of the device of FIG. 1A taken along line AA of FIG. 1A, showing elements constituting the device. 1C is a cross-sectional view of the device of FIG. 1A taken along line AA of FIG. 1A showing rotation of the mirror beam.

FIG. 2A is a plan view of an array of digital accelerometers. B shows the element which comprises a device AA of FIG. 2A
2B is a cross-sectional view of the device of FIG. 2A taken along the line. FIG.

FIG. 3A is a plan view of a silicon wafer attached to a dicing tape held in a saw frame. 3B is a cross-sectional view of the silicon wafer of FIG. 3A taken along the line AA of FIG. 3A.

FIG. 4A is a plan view of a sawed wafer mounted in a saw frame held in a centrifuge. 4B is a cross-sectional view of the wafer of FIG. 4A taken along the line AA of FIG. 4A.

FIG. 5 is a schematic side view of a saw frame and wafer held within a spray generating hood.

FIG. 6A is a plan view of a sawed wafer mounted on a saw frame with a protective cover on the exposed dicing tape. 6B is a cross-sectional view of the protective cover and sawed wafer of FIG. 6A taken along the line AA of FIG. 6A.

FIG. 7 is a plan view of a susceptor plate of a plasma reactor modified to receive a saw frame.

FIG. 8 is a cross-sectional view of a completed device wafer that has been electrically tested.

[Explanation of symbols]

 50 element 52 metal beam 54 torsion hinge 58 insulating oxide layer 60, 62, 64 addressing electrode 66, 68 landing electrode

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] November 28, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction content]

[Document name] Statement

Title: Method for manufacturing a microelectromechanical device

[Claims]

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to the field of integrated circuit processing technology, and more particularly to a method of making microelectromechanical devices including deformable micromirror devices.

[0002]

BACKGROUND OF THE INVENTION In order to make integrated circuit (IC) processing cost-effective, individual circuits or devices are generally mass-produced using semiconductor wafers, such that many devices are manufactured simultaneously on one substrate. Has been done. A typical process flow for integrated circuits follows the steps of manufacturing the device, then testing the device, isolating the device, and packaging the device. When the device is separated from the wafer, dicing chips are created that consist of the particles and powder of the wafer. This dicing debris is washed off the surface of the IC prior to bonding the device to the package.

[0003]

Microelectromechanical systems (MEMS) or micromechanical devices must undergo and withstand some of the standard IC manufacturing processes such as device isolation and cleaning. , Often have structures that are overly fragile. Some ME
MS, eg digital micromirror device (DM
Due to D) and the fragile nature of some accelerometers, standard IC process steps must be rearranged to prevent the finished device from being destroyed. D
The MD is described in US Pat. No. 5,061,049, entitled "Spatial Light Modulator and Method," assigned to Texas Instruments Incorporated. Accelerometer
US Patent Application No. 07 entitled "Digital Accelerometer", assigned to Texas Instruments, Inc.
/ 883,616. As described in the above patents, these MEMS have microstructures suspended over an air gap above electrodes formed on the surface of a silicon substrate. Forming these structures,
Etching away sacrificial material from the air gap makes these devices extremely fragile. These devices are inaccessible to liquids such as those that occur during the wafer cleaning process without fear of breaking the mirror.
Therefore, these devices must be cut and the dicing debris cleaned prior to etching the sacrificial material from the underlying mirror.

Separating the wafer before completing the device results in handling a wide range of devices during the rest of the device manufacturing process, such as passivation and device testing. Performing these processes at the wafer state, unlike the device state, significantly reduces the handling required. The reason is that the processing equipment only needs to move and align one wafer instead of multiple devices. Die tests
Precise alignment is extremely important for towing).

The present invention discloses a method by which wafer processing techniques can be used to complete the entire device manufacturing and test process.

[0006]

In a method of manufacturing a microelectromechanical device or an integrated circuit device,
Mount the partially completed device wafer on dicing tape in a saw frame. The devices are separated by either sawing the wafer or other wafer separation techniques.
Complete device fabrication before removing the device from the dicing tape. In some applications it may be advantageous to cover the exposed adhesive of the dicing tape with a protective cover. The advantage of this method is that the device can be fully processed using efficient industry standard wafer handling techniques.

[0007]

DETAILED DESCRIPTION OF THE INVENTION The method and protective cover disclosed herein are for devices manufactured as microelectromechanical devices having a particularly fragile structure in the wafer, avoiding the use of conventional wafer manufacturing process flows. Applicable to manufacturing. For purposes of illustration, the invention will be described by way of example with reference to the fabrication of digital micromirror devices and accelerometers. The specific embodiments are merely illustrative of possible configurations of the invention and are not intended to limit the invention to the manufacture of DMDs or accelerometers only. The methods disclosed herein can be used with any type of integrated circuit or microelectromechanical device.

A typical DMD device structure is shown in FIGS. 1A-1C. The elements shown are not to scale for all of the drawings included in this disclosure. In most cases, wafer and device layer thicknesses are greatly exaggerated for purposes of illustration. The DMD generally consists of an array of elements 50. Each DMD element 50 typically includes two torsion hinges (torsi) on a silicon substrate 56.
metal beam 5 suspended by an on hinge 54
It consists of two. An insulating oxide layer 58 is grown on the silicon substrate 56, and addressing electrodes 60, 62, 6 are formed on the oxide layer 58.
4 and landing electrodes 66, 68 are deposited. A planarizing (planarizing) spacer layer 68, sometimes referred to as a sacrificial layer, is formed on the substrate, and a hinge metal layer 70 is deposited on the spacer layer 68 followed by a beam metal layer 72. The metal layer is etched to form the beam 52 and hinge 54 of each element 50.

In a typical process flow for DMD fabrication, the devices must be separated by usually sawing between rows of devices on the wafer before undercutting the mirror. Spacer layer 6 below beam 52 and hinge 54 after device isolation
8 is etched away to allow the beam to twist on the hinge as shown in FIG. 1C. This undercut operation is usually performed in the plasma reactor. Access holes 74 and gaps 76 allow the plasma to etch away spacer material 68 below beam 52 and hinges 54. After etching away the spacer layer 68, the device is made chemically less reactive by a process called passivation.

A similar process flow is used to manufacture some accelerometers. 2A and 2B show an array of cantilever accelerometers 78. Beam 8 for each accelerometer
4 comprises a precision mass called a proof mass 80 supported by a hinge 82 attached to the 4. Below each accelerometer is a contact 86, which is deposited on a silicon substrate 88 covered by an insulating oxide layer 90. Planarized spacer layer 92 separates beam 84 and electrode 86. After removing the spacer layer from below the proof mass 80 and the hinge 82 by etching, the proof mass 80 is sufficiently accelerated.
Can be deflected to contact the contact 86.

Spacer layer 68 or 92 as described above
Once etched away, the device becomes extremely brittle and cannot contact the liquid without destroying it, for example during the wafer cleaning process. Since the finished devices are non-cleanable, they are typically separated by sawing before being etched away from the spacer layer. After being separated by sawing, these devices are handled separately during the undercut, die test and protective overcoat processes.

The present invention allows for centralized processing of all devices from a single wafer during the manufacturing process. According to one embodiment of the illustrated invention shown in FIGS. 3A and 3B, a silicon wafer 20 containing a partially completed microelectromechanical device is bonded to a bonding side 21 of a dicing tape 22 held on a saw frame 24. Attached to. FIG. 3B is a sectional view of the wafer 20 on the dicing tape 22 in the saw frame 24.

Wafer 20 is typically silicon,
Other materials such as quartz or gallium arsenide can also be used. To prevent the wafer from being destroyed during the sawing operation, a temporary protective coating can be applied to the surface of the wafer 20 prior to attachment to the wafer in the saw frame. The saw frame is optionally attached so that the devices can be separated by sawing. The saw cuts completely through the wafer and into the dicing tape. However, the dicing tape is not completely cut. For example,
If the thickness of the dicing tape is about 0.1 mm (4 mil), only about 0.025 mm (1 mil) of it will be cut.

After separating the wafer by sawing,
Particles generated during the sawing operation are generally cleaned from the wafer, dicing tape and sawing frame. Once the temporary protective coating has been applied to the wafer, the sawframe can be attached by a centrifuge and the wafer sprayed with solvent to remove the protective coating. 4A and 4B show saw wafer 24 and saw frame 24 attached to centrifuge 28. The dimensions and placement of the device shown in FIG. 4A are for illustration only. Individual devices are shown in FIG. 4B for clarity. Once installed in the centrifuge, the surface of the wafer is sprayed with solvent to remove the protective coating. The centrifuge spins off the solvent and the dissolved coating from the wafer.

Another method of removing the temporary protective coating in the centrifuge is to install a saw frame in the spray generating hood. FIG. 5 shows the saw frame 24 and wafer 26 mounted within the spray generating hood 30. The solvent 32 is sprayed from the spray nozzle 34 onto the surface of the sawed wafer 26 in a state where the solvent 32 is positioned inside the spray generation hood. Solvent gas 36 is removed through a vent 38 at the rear of the hood. The solvent and particles 40 exit the hood through a drain 42 provided at the bottom of the hood.

After removing the protective coating from the wafer, some of the spacer layer 68 or 92 must be removed to leave the mirror or accelerometer support beam. This undercut operation is generally performed in a plasma reactor. Adhesive 2 on dicing tape 22
A protective cover can be placed on the exposed adhesive 21 of the dicing tape 22 in order to prevent contact with the plasma on the substrate 1. 6A and 6B show sawed wafer 26 with protective cover 44 attached to saw frame 24 provided on exposed adhesive 21 of dicing tape 22. For simplicity, the individual devices are not shown in Figure 6B. The protective cover 44 can be made of a material that can withstand exposure to the plasma reactor. For example, the cover can be in the form of a ceramic ring or donut attached to dicing tape. Another method is to use another portion of the dicing tape that is cut to the proper shape and attached so that the adhesive surfaces of the protective cover 44 and the dicing tape used as the dicing tape 22 are mated. The protective cover may be quartz or metal or other material capable of withstanding a plasma etching environment. The sawframe with the sawed wafer and protective cover attached uses a plasma etching process to undercut the mirror or accelerometer beam while retaining the susceptor designed to hold the sawframe.
can be installed on the plate. FIG. 7 shows a susceptor plate 4 with a recessed area 48 adapted to hold the saw frame 24 during the plasma etching process.
6 is shown.

After the undercutting operation, the device can be passivated and electrically and optically tested while still attached to the saw frame. Testing must be greatly simplified because the wafer is still intact in nature because the individual devices 24 must be aligned with each other. Therefore, as shown in FIG. 8, the probe card 49 of the multi-prober is used to align each device 2 with the sawed wafer.
It must be able to match 7 exactly. Movement of the devices on the dicing tape allows each device to be aligned separately using a visually assisted multi-prober.

After testing the device, the device can be removed from the dicing tape and the saw frame and wafer can be mounted on a pick and place machine so that the device rests on the lead frame for the package assembly process. The device removal process of the improved process flow taught by the present invention is a standard IC
Must be identical to the device removal process. Therefore, no changes are required to the device removal and packaging assembly process.

Thus, prior to completing the fabrication of the device, a particular embodiment for a microelectromechanical device for separating the device from the wafer has been described, and such a particular reference is set forth in the following claims. It should not be considered as limiting the scope of the invention, except as noted. Although the invention has been described with reference to certain specific embodiments, further modifications will occur to those skilled in the art, and such modifications should be considered to be covered by the appended claims. Is.

Regarding the above description, the following items will be disclosed. (1) Providing a part of the dicing tape having an adhesive surface,
Attaching a wafer containing a partially manufactured device to the adhesive surface of the dicing tape, subdividing the wafer, separating the partially manufactured device and leaving it mounted on the dicing tape, A method for producing a microelectromechanical device, which comprises the steps of continuously producing separated devices and removing the device from the dicing tape. (2) The method according to claim 1, further comprising the step of placing a protective cover on the exposed portion of the adhesive surface of the dicing tape. (3) The method according to claim 2, wherein the protective cover is selected from the group consisting of ceramic, metal, quartz and dicing tape. (4) The method of claim 1, further comprising applying a temporary protective coating to the device prior to the subdividing step. (5) The method of claim 4, further comprising the step of removing the temporary protective coating from the device. (6) The method according to item 1, wherein the device is a digital micromirror device (DMD). (7) The method according to item 1, wherein the device is an accelerometer. (8) The method of claim 1, wherein the continuing manufacturing step includes plasma etching the device. (9) The method of claim 1, wherein the subsequent manufacturing step includes passivating the device. (10) The method of claim 1, wherein the continuing manufacturing step includes testing the device.

(11) A part of a dicing tape having an adhesive surface is provided, a wafer containing a partially manufactured digital micromirror device is attached to the adhesive surface of the dicing tape, the wafer is subdivided, and the part is formed. Separately manufactured digital micromirror device is separated and left mounted on the dicing tape,
A protective cover selected from the group consisting of ceramic, metal, quartz and dicing tape is placed on the exposed portion of the adhesive surface of the dicing tape, and the manufacturing of the separated digital micromirror device is continued. A method of manufacturing a digital micromirror device including steps of removing a mirror device. (12) The method according to claim 11, wherein the continuing manufacturing step includes plasma etching the digital micromirror device. (13) The method according to item 11, wherein the continuing manufacturing step includes passivating the digital micromirror device. (14) The method according to item 11, wherein the continuing manufacturing step includes testing the digital micromirror device. (15) The method of claim 11, further comprising applying a temporary protective coating to the digital micromirror device before the sub-dividing step. 16. The method of claim 15, further comprising the step of removing the temporary protective coating from the digital micromirror device.

(17) A part of a dicing tape having an adhesive surface is provided, a wafer including a partially manufactured accelerometer is attached to the adhesive surface of the dicing tape, the wafer is subdivided, and the partially The manufactured accelerometer is separated and left mounted on the dicing tape, and a protective cover selected from the group consisting of ceramic, metal, quartz and dicing tape is placed on the exposed portion of the adhesive surface of the dicing tape, A method of manufacturing an accelerometer, which comprises the steps of continuing to manufacture the separated accelerometer and removing the accelerometer from the dicing tape. (18) The method of claim 17, wherein the continuing manufacturing step includes plasma etching the accelerometer. (19) The method of claim 17, wherein the continuing manufacturing step includes passivating the accelerometer. (20) The method of claim 17, wherein the continuing manufacturing step includes testing the accelerometer.

(21) A method for processing a wafer containing microelectromechanical devices that allows all manufacturing and testing steps to be performed in the wafer state rather than the device state. Dicing tape 22
The wafer 20 is mounted in the upper saw frame 24 and the individual devices 27 are separated, typically by sawing, before device fabrication is complete. These devices are left on the dicing tape during other manufacturing steps. In some manufacturing processes it is necessary to cover the adhesive of the dicing tape with a protective cover 44. After completing all manufacturing steps, including applying protective overcoat and functional testing, remove the device from the dicing tape and package.

[Brief description of drawings]

FIG. 1A is a perspective view of one element of a digital micromirror device. 1B is a cross-sectional view of the device of FIG. 1A taken along line AA of FIG. 1A, showing elements constituting the device. 1C is a cross-sectional view of the device of FIG. 1A taken along line AA of FIG. 1A showing rotation of the mirror beam.

FIG. 2A is a plan view of an array of digital accelerometers. B shows the element which comprises a device AA of FIG. 2A
2B is a cross-sectional view of the device of FIG. 2A taken along the line. FIG.

FIG. 3A is a plan view of a silicon wafer attached to a dicing tape held in a saw frame. 3B is a cross-sectional view of the silicon wafer of FIG. 3A taken along the line AA of FIG. 3A.

FIG. 4A is a plan view of a sawed wafer mounted in a saw frame held in a centrifuge. 4B is a cross-sectional view of the wafer of FIG. 4A taken along the line AA of FIG. 4A.

FIG. 5 is a schematic side view of a saw frame and wafer held within a spray generating hood.

FIG. 6A is a plan view of a sawed wafer attached to a saw frame with a protective cover on the exposed dicing tape. 6B is a cross-sectional view of the protective cover and sawed wafer of FIG. 6A taken along the line AA of FIG. 6A.

FIG. 7 is a plan view of a susceptor plate of a plasma reactor modified to receive a saw frame.

FIG. 8 is a cross-sectional view of a completed device wafer that has been electrically tested.

[Explanation of reference numerals] 50 element 52 metal beam 54 torsion hinge 58 insulating oxide layer 60, 62, 64 addressing electrode 66, 68 landing electrode ───────────────────── ──────────────────────────────────

[Procedure amendment]

[Submission date] December 20, 1994

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 4

[Correction method] Change

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[Figure 4]

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 5

[Correction method] Change

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[Figure 5]

[Procedure 3]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 6

[Correction method] Change

[Correction content]

[Figure 6]

Claims (1)

[Claims] 1. A part of a dicing tape having an adhesive surface is provided, a wafer including a partially manufactured device is attached to the adhesive surface of the dicing tape, the wafer is subdivided, and the partially manufactured wafer is manufactured. A method for manufacturing a microelectromechanical device, comprising: separating the device and leaving the device mounted on the dicing tape, continuing the manufacturing of the separated device, and removing the device from the dicing tape.