Classifications

• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P52/00—Grinding, lapping or polishing of wafers, substrates or parts of devices
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P72/00—Handling or holding of wafers, substrates or devices during manufacture or treatment thereof
  • H10P72/04—Apparatus for manufacture or treatment
  • H10P72/0402—Apparatus for fluid treatment
  • H10P72/0406—Apparatus for fluid treatment for cleaning followed by drying, rinsing, stripping, blasting or the like
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P52/00—Grinding, lapping or polishing of wafers, substrates or parts of devices
  • H10P52/40—Chemomechanical polishing [CMP]
  • H10P52/403—Chemomechanical polishing [CMP] of conductive or resistive materials
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P70/00—Cleaning of wafers, substrates or parts of devices
  • H10P70/20—Cleaning during device manufacture
  • H10P70/23—Cleaning during device manufacture during, before or after processing of insulating materials
  • H10P70/237—Cleaning during device manufacture during, before or after processing of insulating materials the processing being a planarisation of insulating layers
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P70/00—Cleaning of wafers, substrates or parts of devices
  • H10P70/20—Cleaning during device manufacture
  • H10P70/27—Cleaning during device manufacture during, before or after processing of conductive materials, e.g. polysilicon or amorphous silicon layers
  • H10P70/277—Cleaning during device manufacture during, before or after processing of conductive materials, e.g. polysilicon or amorphous silicon layers the processing being a planarisation of conductive layers
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P95/00—Generic processes or apparatus for manufacture or treatments not covered by the other groups of this subclass
  • H10P95/06—Planarisation of inorganic insulating materials
  • H10P95/062—Planarisation of inorganic insulating materials involving a dielectric removal step

Definitions

• the invention relates to a method for cleaning a surface of a semiconductor wafer after a chemical-mechanical polishing step and a device for carrying out such a method.
• chemical mechanical polishing is increasingly being used to planarize the topography on the semiconductor wafer that occurs during the production processes.
• the chemical mechanical polishing mainly serves to level trench fillings, metal plugs, e.g. made of tungsten in contact holes and vias and of intermediate oxides and intermetallic dielectrics.
• the semiconductor wafer to be processed is pressed by a wafer carrier against a rotatably arranged polishing table on which there is an elastic perforated pad, a so-called pad, which contains a polishing agent, a so-called slurry.
• the semiconductor wafer and the polishing table rotate in opposite directions, as a result of which the surface of the semiconductor wafer is polished off at the protruding points until a completely flat wafer surface is reached.
• the polishing agents generally contain further active chemical additives which enable selective removal of the layers on the semiconductor wafer.
• a so-called blind polishing process ie a polishing process that is stopped within the layer to be polished
• a so-called stop-ayer polishing process in which the polishing process is selective to another one lying below the polishing layer Layer
• slurry impurities generally remain on the surface of the semiconductor wafer and have to be removed in a subsequent cleaning process.
• the semiconductor wafers are first stored in a water bath after the polishing process and then freed from the surface contamination with a brush apparatus, a so-called brush cleaner.
• the semiconductor wafer is continuously rinsed with distilled water and / or ammonia.
• the semiconductor wafer is then dried in a drying station by rapid rotation.
• the brush cleaning process shown is a single disk process so that the disk throughput remains severely restricted.
• the necessary loading and unloading of the brush cleaner and the spin dryer also make the cleaning process very time-consuming. There is also a high consumption of distilled water or ammonia during the brush cleaning process.
• a wet cleaning process with the aid of chemical baths is also used, in which the semiconductor wafer is drawn through several successive cleaning baths, in particular the chemically bound slurry residues on the semiconductor surface being removed.
• a rinsing with distilled water and then a disk drying is carried out, the so-called Marangoni drying process preferably being used here, in which the semiconductor wafers are pulled through an isopropanol solution and then dried in hot nitrogen.
• the wet chemical cleaning process shown it is possible to clean several semiconductor wafers at the same time, which enables a high throughput of writing to be achieved.
• the problem here remains the high consumption of chemicals in the cleaning process and the high equipment costs.
• the object of the invention is therefore to provide a method and apparatus can remove with which remaining on a semiconductor wafer in chemical mechanical polishing, impurities quickly and effectively with little effort apparati ⁇ ven.
• the semiconductor wafer is first rinsed in succession with an etching liquid, then preferably rinsed with distilled water and then preferably dried with an isopropanol-nitrogen mixture.
• This integrated process control makes it possible to summarize the process steps previously carried out separately during cleaning, which saves process time and at the same time significantly increases the throughput of the disks.
• etching chemistry and distilled water can be saved to a great extent, in particular by carrying out the cleaning process with constant disk rotation.
• an HF solution, a buffered HF solution or a solution of H 2 SO 4 , H 2 O 2 and HF is used as the etching liquid.
• Such etching solutions can be used to reliably remove slurry impurities, such as those that occur in particular in the case of oxide or metal planarization with the aid of a chemical-mechanical polishing process.
• the cleaning device according to the invention has a process chamber which has a loading and unloading station for the semiconductor wafers, a turntable for holding and rotating the semiconductor wafer and feed and return lines for the process media for cleaning the semiconductor wafers.
• the process chamber for the cleaning and drying process is connected directly to the device for chemical mechanical polishing via a wet handler. This enables an integrated polishing and cleaning process with which a minimum defect density on the semiconductor wafer is guaranteed.
• Figure 1 shows schematically a combination system consisting of a chemical mechanical polishing system and a cleaning station according to the invention.
• 2A shows a blind polishing process
• 2B shows a stop layer polishing process
• Fig. 4 shows a cleaning station according to the invention in a sectional view.
• Nes layer structure consisting of a silicon layer 41 with trenches, a thin Si 2 N 3 layer 43 arranged thereon and a thick SiO 2 layer 44 is shown, the polishing process is stopped when the Si 2 N lying under the SiO 2 layer 44 3 layer 42 is exposed.
• the endpoint detection can z. B. done by measuring the current consumption of the rotating disc carrier, since the current changes during the transition of the layer materials.
• the problem with chemical mechanical polishing is that slurry residues adhering to the semiconductor surface have to be removed after the polishing process.
• This cleaning takes place according to the invention in the cleaning system 3, the essential elements of which are shown in more detail in a sectional view in FIG. 4.
• the semiconductor wafer 4 to be cleaned is transferred directly from the polishing system 1 into the cleaning station 3 with the aid of the wet handler 2.
• the wet handler 2 comprises a water bath 21 in which the semiconductor wafer to be cleaned is temporarily stored in order to then move it to the cleaning station 3.
• This coherent structure of the polishing system 1 and cleaning station 3 considerably simplifies the process implementation and significantly reduces the risk of defects forming on the semiconductor surface during the transition from the polishing system to the cleaning station.
• the cleaning station 3 has a loading and unloading station 31 which is connected to the wet handler 2 and to which a cleaning chamber 32 is connected.
• This cleaning chamber 32 is designed essentially cylindrical and divided into a plurality of vertically arranged subchambers, in the embodiment shown four stations, between which a rotatably mounted table 33 can be moved.
• the semiconductor wafer 4 to be cleaned is arranged on this turntable 33, the semiconductor wafer being held only at the edge, so that front and rear side cleaning is possible at the same time.
• F- tQ s co co P- ⁇ ⁇ tQ (D C ⁇ ⁇ ⁇ 3 tQ F. 3 J ⁇ 3 ⁇ to iQ TJ d iQ TJ D do rr Di F D-.
• slurry residues which occur during the planarization of tungsten with the aid of chemical mechanical polishing are to be removed, this is preferably carried out using the following process sequence.
• rinsing with distilled water and then etching off the slurry residues with HF or dilute sulfuric acid with small amounts of HF and H 2 O 2 are carried out in the individual subchambers.
• the semiconductor wafer is then rinsed again with distilled water and then dried in the fourth subchamber with an isopropanol / nitrogen gas mixture at high speed.
• This process sequence also ensures effective and quick removal of slurry residues that remain in a tungsten planarization by means of mechanical-chemical polishing.
• the process sequence according to the invention can in principle be adapted to all impurities which can occur during mechanical-chemical polishing. It is therefore within the scope of the invention to modify the specified materials and processes in a suitable manner in addition to the exemplary embodiments shown in order to remove residues which remain on a semiconductor wafer during mechanical-chemical polishing.
• the features of the invention disclosed in the above description, the drawings and the claims can be of importance both individually and in any combination for realizing the invention in its various configurations.

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• Mechanical Treatment Of Semiconductor (AREA)
• Cleaning Or Drying Semiconductors (AREA)

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Applications Claiming Priority (2)

Related Child Applications (1)

Publications (1)

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Citations (8)

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• 2000
  • 2000-10-25 DE DE10052762A patent/DE10052762A1/de not_active Withdrawn
• 2001
  • 2001-10-08 WO PCT/EP2001/011582 patent/WO2002035598A1/de not_active Ceased
  • 2001-10-08 JP JP2002538478A patent/JP2004512693A/ja active Pending
  • 2001-10-08 EP EP01988947A patent/EP1328968A1/de not_active Withdrawn
  • 2001-10-08 KR KR1020037005115A patent/KR100543928B1/ko not_active Expired - Fee Related
• 2003
  • 2003-04-25 US US10/424,173 patent/US6833324B2/en not_active Expired - Fee Related

Patent Citations (8)

Non-Patent Citations (1)

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