US20180233376A9 - Dry etching method - Google Patents
Dry etching method Download PDFInfo
- Publication number
- US20180233376A9 US20180233376A9 US15/546,475 US201615546475A US2018233376A9 US 20180233376 A9 US20180233376 A9 US 20180233376A9 US 201615546475 A US201615546475 A US 201615546475A US 2018233376 A9 US2018233376 A9 US 2018233376A9
- Authority
- US
- United States
- Prior art keywords
- dry etching
- etching method
- protective gas
- etching
- predetermined
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 54
- 238000001312 dry etching Methods 0.000 title claims abstract description 42
- 238000005530 etching Methods 0.000 claims abstract description 112
- 239000007789 gas Substances 0.000 claims abstract description 89
- 230000001681 protective effect Effects 0.000 claims abstract description 51
- 239000001257 hydrogen Substances 0.000 claims abstract description 34
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 34
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 31
- 238000002347 injection Methods 0.000 claims description 3
- 239000007924 injection Substances 0.000 claims description 3
- 230000000694 effects Effects 0.000 abstract description 9
- 239000000758 substrate Substances 0.000 abstract description 7
- 210000002381 plasma Anatomy 0.000 description 28
- 150000002500 ions Chemical class 0.000 description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 150000002431 hydrogen Chemical class 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 229920002120 photoresistant polymer Polymers 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 239000010409 thin film Substances 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 239000007795 chemical reaction product Substances 0.000 description 2
- 238000004880 explosion Methods 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 125000004429 atom Chemical group 0.000 description 1
- 238000001311 chemical methods and process Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000004973 liquid crystal related substance Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 238000001020 plasma etching Methods 0.000 description 1
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 1
- 229920005591 polysilicon Polymers 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Images
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
- 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
- H01L21/306—Chemical or electrical treatment, e.g. electrolytic etching
- H01L21/3065—Plasma etching; Reactive-ion etching
-
- 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
- H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
- H01L21/3105—After-treatment
- H01L21/311—Etching the insulating layers by chemical or physical means
- H01L21/31105—Etching inorganic layers
- H01L21/31111—Etching inorganic layers by chemical means
- H01L21/31116—Etching inorganic layers by chemical means by dry-etching
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
- H01J37/32—Gas-filled discharge tubes
- H01J37/32431—Constructional details of the reactor
- H01J37/3244—Gas supply means
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
- H01J37/32—Gas-filled discharge tubes
- H01J37/32431—Constructional details of the reactor
- H01J37/32798—Further details of plasma apparatus not provided for in groups H01J37/3244 - H01J37/32788; special provisions for cleaning or maintenance of the apparatus
- H01J37/32853—Hygiene
- H01J37/32871—Means for trapping or directing unwanted particles
-
- 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
- H01L21/306—Chemical or electrical treatment, e.g. electrolytic etching
- H01L21/3065—Plasma etching; Reactive-ion etching
- H01L21/30655—Plasma etching; Reactive-ion etching comprising alternated and repeated etching and passivation steps, e.g. Bosch process
-
- 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
- H01L21/76801—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics characterised by the formation and the after-treatment of the dielectrics, e.g. smoothing
- H01L21/76802—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics characterised by the formation and the after-treatment of the dielectrics, e.g. smoothing by forming openings in dielectrics
- H01L21/76805—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics characterised by the formation and the after-treatment of the dielectrics, e.g. smoothing by forming openings in dielectrics the opening being a via or contact hole penetrating the underlying conductor
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/136—Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
- G02F1/1362—Active matrix addressed cells
- G02F1/1368—Active matrix addressed cells in which the switching element is a three-electrode device
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F2202/00—Materials and properties
- G02F2202/10—Materials and properties semiconductor
- G02F2202/104—Materials and properties semiconductor poly-Si
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J2237/00—Discharge tubes exposing object to beam, e.g. for analysis treatment, etching, imaging
- H01J2237/32—Processing objects by plasma generation
- H01J2237/33—Processing objects by plasma generation characterised by the type of processing
- H01J2237/334—Etching
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J2237/00—Discharge tubes exposing object to beam, e.g. for analysis treatment, etching, imaging
- H01J2237/32—Processing objects by plasma generation
- H01J2237/33—Processing objects by plasma generation characterised by the type of processing
- H01J2237/334—Etching
- H01J2237/3343—Problems associated with etching
- H01J2237/3347—Problems associated with etching bottom of holes or trenches
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/02—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers
- H01L27/12—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being other than a semiconductor body, e.g. an insulating body
- H01L27/1214—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being other than a semiconductor body, e.g. an insulating body comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
- H01L27/1259—Multistep manufacturing methods
Definitions
- the present disclosure relates to a dry etching method, and pertains to a field of semiconductor technologies.
- Dry etching is a technique for thin film etching using plasma.
- Gases have the following two characteristics when existing in the form of plasma: on one hand, chemical activity of the gases in plasma is much higher than that in a normal state, the appropriate gas is selected according to different etched materials, quicker reaction with the materials can be realized to achieve the objective of etching and removal; and on the other hand, the plasma can also be guided and accelerated by an electric field so that the plasma has certain energy, and thus when the plasma bombards the surface of an object being etched, the plasma can hit out atoms of the materials of the etched object. In this way, the objective of etching can be achieved by physical energy transfer.
- dry etching is a result of balance of a physical process and a chemical process on a wafer surface.
- the general dry etching method is as below: molecules or molecular groups capable of producing ion chemical reaction with a thin film are generated using glow discharge of a particular gas (or a mixed gas) under a pressure of 10 ⁇ 1,000 Pa, and the generated reaction product is volatile. Next, the generated reaction product is pumped away in a low-pressure vacuum chamber. In this way, etching can be achieved.
- positive/negative charges may be accumulated in a local area of the substrate due to nonuniformity of distribution of the plasma in an etch chamber.
- the presence of a plasma sheath makes ions and electrons distribute in different locations: the electrons are accumulated on a side wall of an etching trench, whereas the ions are accumulated at the bottom of the trench. As shown in FIG.
- some microetching 2 may occur because a direction of physical etching is changed due to an effect of the electrons accumulated on the side wall of the etching trench on positive ions in etching gas, wherein 1 represents a photoresist layer, 5 represents a buffer layer, and 6 represents the substrate.
- the microetching may cause a decrease of stability and reliability of a liquid crystal display panel.
- the embodiments of the present disclosure may at least partially reduce the microetching effect during dry etching.
- the embodiments of the present disclosure provides a dry etching method, including performing at least two etching steps within an etch chamber, and adding plasma into an etch chamber between any two successive etching steps, wherein the plasma neutralizes electrons accumulated on a side wall of an etching trench.
- adding plasma further includes injecting protective gas, and processing the protective gas to generate the plasma.
- the method further includes removing an etching gas in the etch chamber before adding the plasma.
- removing the etching gas in the etch chamber further includes setting a source power or bias voltage to zero, and injecting the protective gas at a predetermined pressure and a predetermined flow rate within a predetermined time.
- the predetermined pressure is 50 millitorr (mTorr)
- the predetermined flow rate is 1,000 standard cubic centimeter per minute (sccm)
- the predetermined time is 10 seconds (s).
- the method further includes removing the protective gas in the etch chamber after adding the plasma.
- removing the protective gas in the etch chamber further includes setting a source power or bias voltage to zero, and injecting a predetermined amount of an etching gas at a predetermined pressure.
- a pressure of the etch chamber and a gas flow/flow rate of the injected etching gas are equal to those in a next etching step.
- an injection time of the etching gas is 10 seconds (s).
- adding a plasma into an etch chamber further includes setting a predetermined chamber pressure, a predetermined source power, and a predetermined bias voltage, and injecting the protective gas at a predetermined flow rate within a predetermined time.
- the predetermined chamber pressure is 50 millitorr (mTorr)
- the predetermined source power is 500 watts (W)
- the predetermined bias voltage is 0 volts (V)
- the predetermined flow rate is 1,000 standard cubic centimeter per minute (sccm)
- the predetermined time is 10-20 seconds (s).
- the two successive etching steps include a main etching step and an over etching step, wherein the dry etching method further includes injecting a protective gas into the etch chamber for processing between the main etching step and the over etching step.
- the protective gas is hydrogen
- hydrogen plasma is added in an etching process to remove the electrons accumulated on the side wall of the etching trench so as to reduce the microetching effect in multiple etching. In this way, process stability and reliability of a display substrate are improved.
- FIG. 1 is a schematic diagram of generating the microetching effect by dry etching in the prior art
- FIG. 2 is a schematic flow diagram of a dry etching method according to the present disclosure.
- FIG. 3 is a schematic diagram of avoiding the microetching effect according to dry etching of the present disclosure.
- the present disclosure provides a dry etching method, which includes performing at least two etching steps, and injecting protective gas into an etch chamber for processing between any two successive etching steps.
- the protective gas generates plasma to neutralize electrons accumulated on a side wall of an etching trench.
- the dry etching method further includes injecting protective gas into the etch chamber and making the protective gas generate a plasma to neutralize electrons accumulated on the side wall of the etching trench. Therefore, microetching generated in the subsequent etching step due to the electrons accumulated in the previous etching step can be reduced or even avoided.
- the step of injecting protective gas may be added between any two successive etching steps for the purpose of completing an etching process.
- the dry etching in the present disclosure may be a via hole etching or other etching.
- the dry etching method provided by the present disclosure is described in detail by taking via hole etching as an example in which a step of injecting protective gas is added between main etching and over etching.
- the over etching hole includes a main etching step S 1 and an over etching step S 3 .
- the main etching generally is used for etching a large part of a to-be-etched layer to obtain an ideal section of the side wall of the etching trench.
- the over etching is used for removing etch residues and the remaining to-be-etched layer to achieve penetration, generally a part of an underlying layer of the to-be-etched layer may be etched.
- a step S 2 of injecting protective gas into the etch chamber for processing is further provided between the main etching and the over etching.
- the protective gas generates the plasma to neutralize the electrons accumulated on the side wall of the etching trench (i.e., the via hole).
- the electrons accumulated on the side wall of the via hole are neutralized by the plasma generated by the protective gas during the main etching, so that the microetching in FIG. 1 may be alleviated or even prevented.
- the dry etching method provided by the present disclosure is described in detail as below.
- active gas such as oxygen
- active gas may be used in the process of etching, to prevent a risk (for example, explosion) generated by mixing of the oxygen and the injected protective gas
- the etching gas in the etch chamber needs to be cleared away before injecting the protective gas.
- a source power or bias voltage is set to zero, and the protective gas is injected at a predetermined pressure and a predetermined flow rate within a predetermined time.
- the etching gas may be discharged by the protective gas from the etch chamber.
- the predetermined pressure is 50 millitorr (mTorr)
- the predetermined flow rate is 1,000 standard cubic centimeter per minute (sccm)
- the predetermined time is 10 seconds (s).
- a certain amount of protective gas is injected into the etch chamber in the process of etching, and the protective gas may generate a certain plasma under certain conditions (for example, by powering up).
- the plasma may neutralize the electrons accumulated on the side wall of the etching trench. In this way, the electrons accumulated on the side wall of the etching trench may be removed. Therefore, the microetching effect may be effectively prevented, and the stability and reliability of the display substrate may be improved.
- the protective gas is hydrogen.
- the present disclosure is not limited thereto, and other gases capable of generating plasmas in the etch chamber to neutralize the electrons accumulated on the side wall of the etching trench may still be in the scope of the present disclosure, which are not enumerated herein.
- injecting protective gas into the etch chamber for processing is described in detail according to an exemplary solution where the protective gas is hydrogen.
- the protective gas is hydrogen.
- a predetermined chamber pressure, a predetermined source power and a predetermined bias voltage are set, and the protective gas (hydrogen) is injected at a predetermined flow rate within a predetermined time.
- Particles and electrons generation by hydrogen under predetermined conditions may be as shown in Formula (1):
- the conditions for processing the protective gas injected into the etch chamber are as below: the predetermined chamber pressure is 50 millitorr (mTorr), the predetermined source power is 500 watts (W), the predetermined bias voltage is 0 volts (V), the predetermined flow rate is 1,000 standard cubic centimeter per minute (sccm), and the predetermined time is 10-20 seconds (s).
- the predetermined chamber pressure is 50 millitorr (mTorr)
- the predetermined source power is 500 watts (W)
- the predetermined bias voltage is 0 volts (V)
- the predetermined flow rate is 1,000 standard cubic centimeter per minute (sccm)
- the predetermined time is 10-20 seconds (s).
- oxygen may be used in the process of etching, to prevent a dangerous chemical reaction (for example, explosion) generated by mixing of the injected etching gas and the protective gas in the etch chamber, the hydrogen in the etch chamber needs to be cleared away after the protective gas is injected into the etch chamber for processing.
- the source power or bias voltage is set to zero, and a predetermined amount of etching gas is injected at a predetermined pressure.
- the protective gas may be discharged, by the etching gas, from the etch chamber.
- the pressure of the etch chamber and gas flow/flow rate of the injected etching gas are equal to those in a next etching step, and the time for injecting the etching gas may be 10 seconds (s).
- the dry etching method provided by the present disclosure is described in detail by taking forming a via hole by etching as an example herein below.
- the main etching is employed to etch a large part of the insulating layer 3 beneath a missing part of the photoresist layer 1 without damaging the metal layer 4 (for example, the portion above the dotted line in FIG. 3 is etched) to obtain an ideal section of the side wall of the etching trench.
- the etching gas is removed from the etch chamber.
- the pressure is 50 millitorr (mTorr)
- the predetermined flow rate is 1,000 standard cubic centimeters per minute (sccm)
- the time for injecting hydrogen is 10 seconds (s).
- the etching gas may be discharged, by the hydrogen, from the etch chamber.
- a certain amount of hydrogen is injected into the etch chamber.
- the chamber pressure is 50 millitorr (mTorr)
- the source power is 500 watts (W)
- the bias voltage is 0 volts (V)
- the flow rate is 1,000 standard cubic centimeters per minute (sccm)
- the injection time is 10-20 seconds (s).
- the hydrogen may generate a certain plasma under certain conditions (for example, by powering up).
- the electrons accumulated on the side wall of the etching trench are neutralized by ionized hydrogen particles.
- the hydrogen in the etch chamber needs to be cleared away after the hydrogen is injected into the etch chamber for processing.
- the source power or bias voltage is set to zero, and a predetermined amount of etching gas is injected at a predetermined pressure for a next etching process (namely, over etching).
- the hydrogen may be discharged, by the etching gas, from the etch chamber.
- the over etching is implemented to remove the etching residuals and the residual insulating layer 3 to ensure that the via hole reaches the metal layer 4 .
- etching is carried out twice.
- the present disclosure is not limited to etching twice, and an appropriate number of etching may be carried out as needed.
- a plasma (such as hydrogen plasma) is added in an etching process to remove the electrons accumulated on the photoresist layer 1 so as to reduce the microetching effect, which is applicable to via hole etching.
- a plasma such as hydrogen plasma
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Manufacturing & Machinery (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Plasma & Fusion (AREA)
- Analytical Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Epidemiology (AREA)
- Public Health (AREA)
- Drying Of Semiconductors (AREA)
Abstract
Description
- This patent application is a National Stage Entry of PCT/CN2016/078687 filed on Apr. 7, 2016, which claims the benefit and priority of Chinese Patent Application No. 201510226706.4 filed on May 6, 2015, the disclosures of which are incorporated herein by reference as a part of the present application.
- The present disclosure relates to a dry etching method, and pertains to a field of semiconductor technologies.
- Dry etching (or dry etching technique) is a technique for thin film etching using plasma. Gases have the following two characteristics when existing in the form of plasma: on one hand, chemical activity of the gases in plasma is much higher than that in a normal state, the appropriate gas is selected according to different etched materials, quicker reaction with the materials can be realized to achieve the objective of etching and removal; and on the other hand, the plasma can also be guided and accelerated by an electric field so that the plasma has certain energy, and thus when the plasma bombards the surface of an object being etched, the plasma can hit out atoms of the materials of the etched object. In this way, the objective of etching can be achieved by physical energy transfer. Therefore, dry etching is a result of balance of a physical process and a chemical process on a wafer surface. The general dry etching method is as below: molecules or molecular groups capable of producing ion chemical reaction with a thin film are generated using glow discharge of a particular gas (or a mixed gas) under a pressure of 10˜1,000 Pa, and the generated reaction product is volatile. Next, the generated reaction product is pumped away in a low-pressure vacuum chamber. In this way, etching can be achieved.
- At present, in a deep via-hole plasma etching process of preparation for a low-temperature polysilicon thin-film transistor array substrate, positive/negative charges may be accumulated in a local area of the substrate due to nonuniformity of distribution of the plasma in an etch chamber. Moreover, the presence of a plasma sheath makes ions and electrons distribute in different locations: the electrons are accumulated on a side wall of an etching trench, whereas the ions are accumulated at the bottom of the trench. As shown in
FIG. 1 , to etch a via hole reaching ametal layer 4 on aninsulating layer 3, in the process of etching, somemicroetching 2 may occur because a direction of physical etching is changed due to an effect of the electrons accumulated on the side wall of the etching trench on positive ions in etching gas, wherein 1 represents a photoresist layer, 5 represents a buffer layer, and 6 represents the substrate. The microetching may cause a decrease of stability and reliability of a liquid crystal display panel. - The embodiments of the present disclosure may at least partially reduce the microetching effect during dry etching.
- The embodiments of the present disclosure provides a dry etching method, including performing at least two etching steps within an etch chamber, and adding plasma into an etch chamber between any two successive etching steps, wherein the plasma neutralizes electrons accumulated on a side wall of an etching trench.
- In one embodiment, adding plasma further includes injecting protective gas, and processing the protective gas to generate the plasma.
- In one embodiment, the method further includes removing an etching gas in the etch chamber before adding the plasma.
- In one embodiment, removing the etching gas in the etch chamber further includes setting a source power or bias voltage to zero, and injecting the protective gas at a predetermined pressure and a predetermined flow rate within a predetermined time.
- In one embodiment, the predetermined pressure is 50 millitorr (mTorr), the predetermined flow rate is 1,000 standard cubic centimeter per minute (sccm), and the predetermined time is 10 seconds (s).
- In one embodiment, the method further includes removing the protective gas in the etch chamber after adding the plasma.
- In one embodiment, removing the protective gas in the etch chamber further includes setting a source power or bias voltage to zero, and injecting a predetermined amount of an etching gas at a predetermined pressure.
- In one embodiment, a pressure of the etch chamber and a gas flow/flow rate of the injected etching gas are equal to those in a next etching step.
- In one embodiment, an injection time of the etching gas is 10 seconds (s).
- In one embodiment, adding a plasma into an etch chamber further includes setting a predetermined chamber pressure, a predetermined source power, and a predetermined bias voltage, and injecting the protective gas at a predetermined flow rate within a predetermined time.
- In one embodiment, the predetermined chamber pressure is 50 millitorr (mTorr), the predetermined source power is 500 watts (W), the predetermined bias voltage is 0 volts (V), the predetermined flow rate is 1,000 standard cubic centimeter per minute (sccm), and the predetermined time is 10-20 seconds (s).
- In one embodiment, the two successive etching steps include a main etching step and an over etching step, wherein the dry etching method further includes injecting a protective gas into the etch chamber for processing between the main etching step and the over etching step.
- In one embodiment, the protective gas is hydrogen.
- According to the dry etching method provided by the present disclosure, hydrogen plasma is added in an etching process to remove the electrons accumulated on the side wall of the etching trench so as to reduce the microetching effect in multiple etching. In this way, process stability and reliability of a display substrate are improved.
-
FIG. 1 is a schematic diagram of generating the microetching effect by dry etching in the prior art; -
FIG. 2 is a schematic flow diagram of a dry etching method according to the present disclosure; and -
FIG. 3 is a schematic diagram of avoiding the microetching effect according to dry etching of the present disclosure. - Detailed description of implementations of the present disclosure will further be made with reference to drawings and embodiments in order to make the above objects, technical solutions and advantages of the embodiments of the present disclosure more apparent. The following embodiments are intended to describe the present disclosure but are not intended to limit the scope of the present disclosure. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments described in the present disclosure shall fall within the protection scope of the present disclosure.
- Unless otherwise defined, all the technical or scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which the present disclosure belongs. The terms “first”, “second” and so on used in the specification and claims of the present disclosure do not denote any sequence, quantity or importance, but instead are merely used to distinguish different constituent parts. Likewise, the terms such as “a”, “an” and so on do not indicate quantitative limitation, but indicate the existence of at least one. The terms “connect” or “connection” and so on are not limited to physical or mechanical connection, and also may include electrical connection, either directly or indirectly. “On,” “under,” “right,” “left” and the like are only used to indicate relative position relationship, and when the absolute position of the object which is described is changed, the relative position relationship may be changed accordingly.
- The present disclosure provides a dry etching method, which includes performing at least two etching steps, and injecting protective gas into an etch chamber for processing between any two successive etching steps. The protective gas generates plasma to neutralize electrons accumulated on a side wall of an etching trench. Between any two successive etching steps, the dry etching method further includes injecting protective gas into the etch chamber and making the protective gas generate a plasma to neutralize electrons accumulated on the side wall of the etching trench. Therefore, microetching generated in the subsequent etching step due to the electrons accumulated in the previous etching step can be reduced or even avoided.
- In the present disclosure, the step of injecting protective gas may be added between any two successive etching steps for the purpose of completing an etching process. The dry etching in the present disclosure may be a via hole etching or other etching. For ease of understanding, the dry etching method provided by the present disclosure is described in detail by taking via hole etching as an example in which a step of injecting protective gas is added between main etching and over etching.
- As shown in
FIG. 2 , the over etching hole includes a main etching step S1 and an over etching step S3. The main etching generally is used for etching a large part of a to-be-etched layer to obtain an ideal section of the side wall of the etching trench. Whereas the over etching is used for removing etch residues and the remaining to-be-etched layer to achieve penetration, generally a part of an underlying layer of the to-be-etched layer may be etched. A step S2 of injecting protective gas into the etch chamber for processing is further provided between the main etching and the over etching. In the step S2, the protective gas generates the plasma to neutralize the electrons accumulated on the side wall of the etching trench (i.e., the via hole). Thus, the electrons accumulated on the side wall of the via hole are neutralized by the plasma generated by the protective gas during the main etching, so that the microetching inFIG. 1 may be alleviated or even prevented. The dry etching method provided by the present disclosure is described in detail as below. - In the present disclosure, active gas, such as oxygen, may be used in the process of etching, to prevent a risk (for example, explosion) generated by mixing of the oxygen and the injected protective gas, preferably, the etching gas in the etch chamber needs to be cleared away before injecting the protective gas. When removing the etching gas in the etch chamber, a source power or bias voltage is set to zero, and the protective gas is injected at a predetermined pressure and a predetermined flow rate within a predetermined time. As the protective gas is injected, the etching gas may be discharged by the protective gas from the etch chamber. In one embodiment, when the etching gas is removed, the predetermined pressure is 50 millitorr (mTorr), the predetermined flow rate is 1,000 standard cubic centimeter per minute (sccm), and the predetermined time is 10 seconds (s).
- A certain amount of protective gas is injected into the etch chamber in the process of etching, and the protective gas may generate a certain plasma under certain conditions (for example, by powering up). The plasma may neutralize the electrons accumulated on the side wall of the etching trench. In this way, the electrons accumulated on the side wall of the etching trench may be removed. Therefore, the microetching effect may be effectively prevented, and the stability and reliability of the display substrate may be improved. In one embodiment of the present disclosure, the protective gas is hydrogen. It is to be understood that the present disclosure is not limited thereto, and other gases capable of generating plasmas in the etch chamber to neutralize the electrons accumulated on the side wall of the etching trench may still be in the scope of the present disclosure, which are not enumerated herein. In the following, injecting protective gas into the etch chamber for processing is described in detail according to an exemplary solution where the protective gas is hydrogen. A predetermined chamber pressure, a predetermined source power and a predetermined bias voltage are set, and the protective gas (hydrogen) is injected at a predetermined flow rate within a predetermined time. Particles and electrons generation by hydrogen under predetermined conditions may be as shown in Formula (1):
-
H2→2H++2e− (1) - Ions generated after ionization of hydrogen neutralize the electrons accumulated on the side wall of the etching trench to generate hydrogen, as shown in Formula (2):
-
2H|+2e−→H2 (2) - After a certain amount of hydrogen is injected into the etch chamber, the electrons accumulated on the side wall of the etching trench are neutralized by ionized hydrogen particles. In one embodiment, the conditions for processing the protective gas injected into the etch chamber are as below: the predetermined chamber pressure is 50 millitorr (mTorr), the predetermined source power is 500 watts (W), the predetermined bias voltage is 0 volts (V), the predetermined flow rate is 1,000 standard cubic centimeter per minute (sccm), and the predetermined time is 10-20 seconds (s).
- Since oxygen may be used in the process of etching, to prevent a dangerous chemical reaction (for example, explosion) generated by mixing of the injected etching gas and the protective gas in the etch chamber, the hydrogen in the etch chamber needs to be cleared away after the protective gas is injected into the etch chamber for processing. When removing the protective gas in the etch chamber, the source power or bias voltage is set to zero, and a predetermined amount of etching gas is injected at a predetermined pressure. As the etching gas is injected, the protective gas may be discharged, by the etching gas, from the etch chamber. In one embodiment, when the protective gas is removed, the pressure of the etch chamber and gas flow/flow rate of the injected etching gas are equal to those in a next etching step, and the time for injecting the etching gas may be 10 seconds (s).
- As shown in
FIG. 3 , the dry etching method provided by the present disclosure is described in detail by taking forming a via hole by etching as an example herein below. First, the main etching is employed to etch a large part of the insulatinglayer 3 beneath a missing part of thephotoresist layer 1 without damaging the metal layer 4 (for example, the portion above the dotted line inFIG. 3 is etched) to obtain an ideal section of the side wall of the etching trench. Next, the etching gas is removed from the etch chamber. In one embodiment, the pressure is 50 millitorr (mTorr), the predetermined flow rate is 1,000 standard cubic centimeters per minute (sccm), and the time for injecting hydrogen is 10 seconds (s). As the hydrogen is injected, the etching gas may be discharged, by the hydrogen, from the etch chamber. Next, a certain amount of hydrogen is injected into the etch chamber. In one embodiment, the chamber pressure is 50 millitorr (mTorr), the source power is 500 watts (W), the bias voltage is 0 volts (V), the flow rate is 1,000 standard cubic centimeters per minute (sccm), and the injection time is 10-20 seconds (s). After a certain amount of hydrogen is injected into the etch chamber, the hydrogen may generate a certain plasma under certain conditions (for example, by powering up). The electrons accumulated on the side wall of the etching trench are neutralized by ionized hydrogen particles. To prevent residual hydrogen from reacting with an active gas, such as oxygen, injected into the etching gas during over etching, the hydrogen in the etch chamber needs to be cleared away after the hydrogen is injected into the etch chamber for processing. When removing the hydrogen in the etch chamber, the source power or bias voltage is set to zero, and a predetermined amount of etching gas is injected at a predetermined pressure for a next etching process (namely, over etching). As the etching gas is injected, the hydrogen may be discharged, by the etching gas, from the etch chamber. Finally, the over etching is implemented to remove the etching residuals and the residual insulatinglayer 3 to ensure that the via hole reaches themetal layer 4. Through the above method, no microetching may occur because the electrons on the side wall of the etching trench are neutralized by the plasma in the hydrogen. - In an embodiment of the present disclosure, etching is carried out twice. However, the present disclosure is not limited to etching twice, and an appropriate number of etching may be carried out as needed.
- In conclusion, according to the dry etching method provided by the present disclosure, a plasma (such as hydrogen plasma) is added in an etching process to remove the electrons accumulated on the
photoresist layer 1 so as to reduce the microetching effect, which is applicable to via hole etching. In this way, the process stability and reliability of a display substrate can be improved. - The above implementations are merely intended for describing the present disclosure, and are not restrictive of the present disclosure. Persons of ordinary skill in the art may make various variations and modifications without departing from the spirit and scope of the present disclosure. Therefore, all equivalent technical solutions also fall within the scope of the present disclosure, and the patent protection scope of the present disclosure shall be limited by the claims.
Claims (20)
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201510226706.4 | 2015-05-06 | ||
CN201510226706.4A CN104779153A (en) | 2015-05-06 | 2015-05-06 | Dry etching method |
CN201510226706 | 2015-05-06 | ||
PCT/CN2016/078687 WO2016177251A1 (en) | 2015-05-06 | 2016-04-07 | Dry etching method |
Publications (3)
Publication Number | Publication Date |
---|---|
US20180025915A1 US20180025915A1 (en) | 2018-01-25 |
US20180233376A9 true US20180233376A9 (en) | 2018-08-16 |
US10468266B2 US10468266B2 (en) | 2019-11-05 |
Family
ID=53620562
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US15/546,475 Active 2036-04-18 US10468266B2 (en) | 2015-05-06 | 2016-04-07 | Dry etching method |
Country Status (3)
Country | Link |
---|---|
US (1) | US10468266B2 (en) |
CN (1) | CN104779153A (en) |
WO (1) | WO2016177251A1 (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104779153A (en) * | 2015-05-06 | 2015-07-15 | 京东方科技集团股份有限公司 | Dry etching method |
CN111463128A (en) * | 2020-04-14 | 2020-07-28 | Tcl华星光电技术有限公司 | Dry etching method and polycrystalline silicon thin film transistor |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6207532B1 (en) | 1999-09-30 | 2001-03-27 | Taiwan Semiconductor Manufacturing Company | STI process for improving isolation for deep sub-micron application |
US7028696B2 (en) * | 2001-05-04 | 2006-04-18 | Lam Research Corporation | Plasma cleaning of deposition chamber residues using duo-step wafer-less auto clean method |
US20040253823A1 (en) * | 2001-09-17 | 2004-12-16 | Taiwan Semiconductor Manufacturing Co. | Dielectric plasma etch with deep uv resist and power modulation |
US8809195B2 (en) * | 2008-10-20 | 2014-08-19 | Asm America, Inc. | Etching high-k materials |
US20110260299A1 (en) * | 2010-04-22 | 2011-10-27 | Endicott Interconnect Technologies, Inc. | Method for via plating in electronic packages containing fluoropolymer dielectric layers |
US9305797B2 (en) * | 2013-01-17 | 2016-04-05 | Applied Materials, Inc. | Polysilicon over-etch using hydrogen diluted plasma for three-dimensional gate etch |
CN104143522B (en) * | 2013-05-09 | 2017-05-24 | 中芯国际集成电路制造(上海)有限公司 | Shallow trench forming method |
CN104779153A (en) | 2015-05-06 | 2015-07-15 | 京东方科技集团股份有限公司 | Dry etching method |
-
2015
- 2015-05-06 CN CN201510226706.4A patent/CN104779153A/en active Pending
-
2016
- 2016-04-07 WO PCT/CN2016/078687 patent/WO2016177251A1/en active Application Filing
- 2016-04-07 US US15/546,475 patent/US10468266B2/en active Active
Also Published As
Publication number | Publication date |
---|---|
US10468266B2 (en) | 2019-11-05 |
WO2016177251A1 (en) | 2016-11-10 |
CN104779153A (en) | 2015-07-15 |
US20180025915A1 (en) | 2018-01-25 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US11410860B2 (en) | Process chamber for etching low k and other dielectric films | |
KR100465947B1 (en) | Plasma processing of tungsten using a gas mixture comprising a fluorinated gas and oxygen | |
US7226868B2 (en) | Method of etching high aspect ratio features | |
CN102870198B (en) | Pole low silicon loss high dose implantation is peeled off | |
US20080081483A1 (en) | Pulsed plasma etching method and apparatus | |
TWI579882B (en) | System, apparatus and method for improving performance of an ion source | |
KR20210042939A (en) | Equipment and process for electron beam mediated plasma etching and deposition process | |
US6693043B1 (en) | Method for removing photoresist from low-k films in a downstream plasma system | |
TWI226086B (en) | Two stage etching of silicon nitride to form a nitride spacer | |
KR101449081B1 (en) | Substrate processing method | |
US8263496B1 (en) | Etching method for preparing a stepped structure | |
KR102104240B1 (en) | Plasma etching method | |
CN109196624B (en) | Etching method | |
US20170345667A1 (en) | Method of silicon extraction using a hydrogen plasma | |
US7642193B2 (en) | Method of treating a mask layer prior to performing an etching process | |
Lim et al. | On the etching characteristics and mechanisms of HfO2 thin films in CF4/O2/Ar and CHF3/O2/Ar plasma for nano-devices | |
US10468266B2 (en) | Dry etching method | |
US10991594B2 (en) | Method for area-selective etching of silicon nitride layers for the manufacture of microelectronic workpieces | |
US20120244693A1 (en) | Method for patterning a full metal gate structure | |
CN102203912A (en) | Improving the conformal doping in p3i chamber | |
US8501628B2 (en) | Differential metal gate etching process | |
CN102779741A (en) | Grid electrode etching method | |
US11682560B2 (en) | Systems and methods for hafnium-containing film removal | |
CN105810579B (en) | Etching method | |
US7410593B2 (en) | Plasma etching methods using nitrogen memory species for sustaining glow discharge |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: BOE TECHNOLOGY GROUP CO., LTD., CHINA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:ZUO, YUEPING;MA, YINGHAI;LI, LIANGJIAN;REEL/FRAME:043102/0887 Effective date: 20170703 |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: NON FINAL ACTION MAILED |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: NOTICE OF ALLOWANCE MAILED -- APPLICATION RECEIVED IN OFFICE OF PUBLICATIONS |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: PUBLICATIONS -- ISSUE FEE PAYMENT VERIFIED |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
CC | Certificate of correction | ||
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 4TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1551); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY Year of fee payment: 4 |