Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
  • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
  • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
  • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
  • H01L21/67005—Apparatus not specifically provided for elsewhere
  • H01L21/67011—Apparatus for manufacture or treatment
  • H01L21/67092—Apparatus for mechanical treatment
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
  • B23K26/12—Working by laser beam, e.g. welding, cutting or boring in a special atmosphere, e.g. in an enclosure
  • B23K26/123—Working by laser beam, e.g. welding, cutting or boring in a special atmosphere, e.g. in an enclosure in an atmosphere of particular gases
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
  • B23K26/14—Working by laser beam, e.g. welding, cutting or boring using a fluid stream, e.g. a jet of gas, in conjunction with the laser beam; Nozzles therefor
  • B23K26/142—Working by laser beam, e.g. welding, cutting or boring using a fluid stream, e.g. a jet of gas, in conjunction with the laser beam; Nozzles therefor for the removal of by-products
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
  • B23K26/18—Working by laser beam, e.g. welding, cutting or boring using absorbing layers on the workpiece, e.g. for marking or protecting purposes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
  • B23K26/36—Removing material
  • B23K26/38—Removing material by boring or cutting
  • B23K26/382—Removing material by boring or cutting by boring
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
  • B23K26/36—Removing material
  • B23K26/38—Removing material by boring or cutting
  • B23K26/382—Removing material by boring or cutting by boring
  • B23K26/389—Removing material by boring or cutting by boring of fluid openings, e.g. nozzles, jets
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
  • B23K26/36—Removing material
  • B23K26/40—Removing material taking account of the properties of the material involved
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28D—WORKING STONE OR STONE-LIKE MATERIALS
  • B28D5/00—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor
  • B28D5/0005—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor by breaking, e.g. dicing
  • B28D5/0011—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor by breaking, e.g. dicing with preliminary treatment, e.g. weakening by scoring
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
  • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
  • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
  • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
  • H01L21/302—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
  • H01L21/304—Mechanical treatment, e.g. grinding, polishing, cutting
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
  • H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
  • H01L21/768—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics
  • H01L21/76898—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics formed through a semiconductor substrate
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
  • H01L21/77—Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate
  • H01L21/78—Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate with subsequent division of the substrate into plural individual devices
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K2101/00—Articles made by soldering, welding or cutting
  • B23K2101/36—Electric or electronic devices
  • B23K2101/40—Semiconductor devices
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K2103/00—Materials to be soldered, welded or cut
  • B23K2103/16—Composite materials, e.g. fibre reinforced
  • B23K2103/166—Multilayered materials
  • B23K2103/172—Multilayered materials wherein at least one of the layers is non-metallic
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K2103/00—Materials to be soldered, welded or cut
  • B23K2103/50—Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S438/00—Semiconductor device manufacturing: process
  • Y10S438/977—Thinning or removal of substrate

Definitions

• the invention relates to machining substrates, particularly, but not limited to, semiconductor wafers.
• a method of machining a substrate comprising the steps of: (a) using a laser emitting visible or ultraviolet radiation to machine a formation in a first surface of the substrate to a predetermined depth from the first surface that is less than a full depth of the substrate; and (b) removing material from a second surface of the substrate opposed to the first surface to the predetermined depth from the first surface to communicate with the formation.
• step (a) comprises laser machining with a laser emitting radiation of a wavelength of one of substantially 266nm, 355nm and 532nm.
• step (a) comprises machining a channel
• step (b) comprises completing a cut through the substrate at the channel.
• step (a) comprises machining a channel with substantially plane opposed side walls between the first surface and the predetermined depth from the first surface and substantially arcuate opposed side walls below the predetermined depth.
• step (a) comprises machining a grid of channels, and step (b) completes dicing of the substrate along the grid of channels.
• step (a) comprises machining a via and metallising the via with metal, and step (b) comprises exposing a portion of the metal in the via at the second surface.
• the step of machining a via comprises machining in a path forming a circle or a plurality of concentric circles to form a via centred on a centre of the circle or the plurality of concentric circles.
• the step of metallising the via includes a prior step of oxidising the via.
• step (a) is performed in a non-ambient controlled gas environment, using at least one of a reactive gas and a passive gas at least one of prior to, during and after laser machining.
• the step of using at least one of a reactive and a passive gas comprises using at least one passive gas substantially inert with respect to the substrate substantially to prevent oxidation of the substrate during laser machining thereof.
• the step of using at least one passive gas comprises using at least one of argon and helium.
• the step of using at least one of a reactive and a passive gas comprises using at least one gas reactive with respect to the substrate, to reduce roughness of laser-machined surfaces formed in step (a).
• the step of using at least one of a reactive and a passive gas comprises using at least one gas reactive with respect to the substrate, to remove debris created in step (a).
• the step of using at least one gas reactive with respect to the substrate comprises using at least one of a chloroflurocarbon-based gas and a halocarbon-based gas.
• step (b) is performed by mechanically removing material, particularly by lapping and polishing.
• step (b) is performed by chemical etching.
• step (b) is performed by plasma etching.
• step (b) is performed by laser ablation.
• step (b) comprises the application of mechanical pressure to the substrate to break the substrate along the channel.
• step (a) comprises a further step of providing a protective layer for the first surface against debris formed in at least one of step (a) and step (b).
• the step of providing a protective layer comprises providing a spin coated layer.
• the step of providing a protective layer comprises providing a tape layer.
• the substrate is of silicon material.
• the substrate is of an optoelectronic material.
• the substrate comprises layers of semiconductor and metal material.
• step (a) comprises laser machining with a Q-switched laser.
• a substrate machining system comprising: laser machining means for emitting visible or ultraviolet radiation for machining a formation in a first surface of a substrate to a predetermined depth from the first surface that is less than a full depth of the substrate; and material removal means for removing material from a second surface of the substrate opposed to the first surface to the predetermined depth from the first surface to communicate with the machined formation.
• the laser machining means is arranged to machine a channel, and the material removal means is arranged to complete a cut through the substrate at the channel.
• the laser machining means is arranged to machine a channel having substantially planar opposed side walls between the first surface and the predetermined depth from the first surface and substantially arcuate opposed walls beyond the predetermined depth.
• the laser machining means is arranged to machine a grid of channels
• the material removal means is arranged to complete dicing of the substrate along the grid of channels.
• the laser machining means is arranged to machine a via
• the system further comprises metallising means for metallising the via
• the material removal means is arranged to expose metal in the via at the second surface.
• the system further comprises oxidising means for oxidising the via prior to metallization.
• the system further comprises gas handling means for providing at least one of a reactive gas environment and a passive gas environment for the substrate at least one of prior to, during and after laser machining.
• the material removal means is mechanical removal means, particularly lapping and polishing means.
• the material removal means is chemical etching means.
• the material removal means is plasma etching means.
• the material removal means is laser ablation means.
• the system is arranged for machining silicon material.
• the system is arranged for machining a substrate comprising layers of semiconductor and metal material
• the system is arranged for machining a substrate comprising optoelectronic material.
• the laser machining means comprises a Q-switched laser.
• the laser machining means is arranged to emit radiation of a wavelength of one of substantially 266nm, 355nm and 532nm.
• Fig. 1 is a plan view of a semiconductor wafer before dicing
• Fig. 2 is a diagrammatic cross-sectional view of the wafer of Figure 1 showing an active region and a support region of the wafer, and a laser- machined channel;
• Fig. 3 is the diagrammatic view of Figure 2 with the support region removed;
• Figs. 4(a), 4(b) and 4(c) are a series of cross-sectional diagrams showing a machining process of the invention.
• Figs. 5(a) and 5(b) are cross-sectional diagrams illustrating an alternative machining process helpful in understanding the invention.
• Figs. 6(a), 6(b), and 6(c) are cross-sectional diagrams illustrating a further embodiment of the machining process of the invention. Modes for Carrying out the Invention
• each die 2 comprises an active region 4 supported by a support region 5 providing mechanical support during manufacture.
• a support region 5 providing mechanical support during manufacture.
• an upper active circuit layer 7 Within the active region 4 there is an upper active circuit layer 7 and a lower final support layer 6.
• the active region 4 is of thickness less than 100 microns.
• the active region 4 may be an integrated electronic circuit but may also be an optical waveguide circuit. It is a requirement that the wafer is sufficiently thick that it is mechanically robust. For large area wafers, e.g. 300mm wafers, typically this thickness may be in the region of 500 microns to 800 microns.
• dicing of the wafer has been performed with dicing saws and throughput has been a function of machining speed, alignment time, and yield.
• the invention employs an alternative technique using a combination of laser street machining and backside wafer thinning.
• a laser is used to scribe a channel 8 (Fig. 2) of depth d and width w into the street region.
• a high power Q-switched laser operating within a band of substantially lOnm centred on 266nm, 355nm or 532nm may be used.
• the street may be machined at high speed without affecting the functionality of devices in the active region 4.
• channels 8 of 20 to 100 microns depth may be machined at speeds up to 80mm/s with appropriate laser settings.
• the channel 8 may have substantially plane opposed side walls between the first surface and a predetermined depth and substantially arcuate opposed walls below the predetermined depth.
• the support region 5 of the wafer is thinned by lapping and polishing, chemical etching, plasma etching, or laser ablation. This thinning provides final separated dies 2 shown in Fig. 3. The result is a diced wafer.
• the active circuit layer 7 is supported by the final support layer 6.
• a Q- switched laser beam 9 is used to drill microvia features 10 through the active circuit layer 7 and supporting substrate layer 6 down to the supporting structure 5 as shown in Fig 4(a).
• the microvias 10 are then metallised with metal 11, to facilitate electrical connection of the active circuit layer 7.
• Drilling of microvias 10 with pulsed lasers may be performed using one of two methods.
• a first method a stationary beam is used (pixel vias). Using this technique a number of laser pulses are delivered to a single point on the substrate. The number of pulses required to reach a certain depth depends on their energy, wavelength and duration. This technique is suitable for vias smaller than approximately 100 microns diameter. The exact via diameter depends on the laser beam diameter, optical and laser parameters and material properties.
• a beam is scanned along the outer profile of the via. This technique is suitable for vias larger than approximately 100 microns diameter. The laser moves in a circular pattern, in a single circle or a plurality of concentric circles. Several repetitions might be required to reach the required depth.
• the via diameter is a function of the radius of the outermost circle and the beam diameter. Such a via is referred to as a scanned or trepanned via.
• a blind microvia structure is formed which is subsequently filled with metal 11 in order to provide a conducting pathway as shown in Fig. 4(b).
• the microvia may be oxidised before metallization.
• the backside of the wafer is then thinned (Fig. 4(c)) by lapping and polishing, chemical etching, or plasma etching in order to expose the metal in the laser machined microvia, thus permitting electrical connection of devices in the active circuit layer to power and ground sources.
• the active device in the case where the wafer on which the active devices are located is thin (typically ⁇ 300 microns), vias are laser machined through the active layer 20 and completely through the supporting substrate 21.
• the via 22 is then metallised with metal 23 subsequent to oxidisation in order to facilitate electrical connection (Fig. 5(b)).
• the active device in a further embodiment of the invention, consists of a series of alternate silicon layers 32 and metal layers 33 as shown in Fig 6(a).
• a Q-switched laser is used to drill a microvia structure 34 from the surface of an active device 35, through this active device layer and into the supporting substrate 36 (Fig. 6(b)).
• the microvia 34 is then metallised with metal 37.
• the backside of the wafer is then thinned (Fig. 6(c)) by lapping and polishing, chemical etching, plasma etching or laser ablation in order to expose the metal layer in the laser machined microvia, thus permitting electrical connection of device layers to power and ground sources.
• the laser machining may be performed in a non-ambient gas environment controlled by a gas handling system.
• Gas parameters such as flow rate, concentration, temperature, gas type and gas mixes are controlled prior to, during and after laser machining.
• a series of gases may be used in succession prior to, during and/or after laser machining.
• the gases used may be passive or reactive with respect to the semiconductor substrate and/or layers in the semiconductor substrate to be machined.
• Inert gases e.g. argon and helium
• gases that react with silicon e.g. chlorofluorocarbons and halocarbons
• a chlorofluorocarbon-based gas and/or a halocarbon-based gas may be used during a laser scan of die sidewalls in order to remove debris located on the sidewalls of the laser machined channel or via.
• a chlorofluorocarbon-based gas and/or a halocarbon-based gas may be used during a laser scan of the outer rim of the machined channel or via in order to remove debris from the top of the laser machined surface.
• the surface of the substrate that the laser is incident upon may be spin coated with a protective layer to prevent debris from the laser machining or mechanical machining steps falling on the active device layer 4.
• the surface of the substrate that the laser is incident may be covered with a tape to act as a protective layer preventing debris from the laser machining or mechanical machining steps falling on the active device layer 4.
• the laser machined surface of the substrate may be coated with a back grinding tape, die attach tape or dicing tape in order to facilitate holding of die after the mechanical machining process.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Mechanical Engineering (AREA)
• Plasma & Fusion (AREA)
• Power Engineering (AREA)
• General Physics & Mathematics (AREA)
• Manufacturing & Machinery (AREA)
• Computer Hardware Design (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Condensed Matter Physics & Semiconductors (AREA)
• Mechanical Treatment Of Semiconductor (AREA)
• Laser Beam Processing (AREA)
• Drying Of Semiconductors (AREA)
• Dicing (AREA)
• Crystals, And After-Treatments Of Crystals (AREA)
• ing And Chemical Polishing (AREA)
• Manufacturing Of Printed Wiring (AREA)
• Internal Circuitry In Semiconductor Integrated Circuit Devices (AREA)
• Processing Of Stones Or Stones Resemblance Materials (AREA)

Priority Applications (6)

Applications Claiming Priority (4)

Publications (3)

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ID=34219649

Family Applications (1)

Country Status (9)

Cited By (7)

Families Citing this family (39)

Family Cites Families (48)

• 2002
  • 2002-10-01 WO PCT/EP2002/011001 patent/WO2003028949A2/en not_active Ceased
  • 2002-10-01 AT AT02800144T patent/ATE327572T1/de not_active IP Right Cessation
  • 2002-10-01 EP EP06004748A patent/EP1677346B1/en not_active Expired - Lifetime
  • 2002-10-01 KR KR1020047004824A patent/KR100913510B1/ko not_active Expired - Fee Related
  • 2002-10-01 JP JP2003532249A patent/JP2005504445A/ja active Pending
  • 2002-10-01 AU AU2002362491A patent/AU2002362491A1/en not_active Abandoned
  • 2002-10-01 AT AT06004748T patent/ATE537558T1/de active
  • 2002-10-01 CN CNB028193709A patent/CN100369235C/zh not_active Expired - Fee Related
  • 2002-10-01 DE DE60211728T patent/DE60211728T2/de not_active Expired - Lifetime
  • 2002-10-01 EP EP02800144A patent/EP1433195B1/en not_active Expired - Lifetime
  • 2002-10-01 US US10/490,985 patent/US8048774B2/en not_active Expired - Fee Related
• 2009
  • 2009-08-21 JP JP2009191614A patent/JP2010016392A/ja active Pending

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