CN103295870A - Plasma etching equipment and etching method - Google Patents
Plasma etching equipment and etching method Download PDFInfo
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- CN103295870A CN103295870A CN2013102220552A CN201310222055A CN103295870A CN 103295870 A CN103295870 A CN 103295870A CN 2013102220552 A CN2013102220552 A CN 2013102220552A CN 201310222055 A CN201310222055 A CN 201310222055A CN 103295870 A CN103295870 A CN 103295870A
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Abstract
Disclosed are plasma etching equipment and an etching method. The plasma etching equipment comprises an etching chamber, a first radiofrequency power source, a second radiofrequency power source, and a power pulse controller. The first radiofrequency power source provides radiofrequency power from 2MHz to 120MHz. The second radiofrequency power source provides radiofrequency power from 2MHz to 40MHz. The power pulse controller controls pulse of the first radiofrequency power source and/or second radiofrequency power source, so that the pulse frequency of the first radiofrequency power source is larger than 1000Hz and/or the pulse frequency of the second radiofrequency power source is smaller than 1000Hz. The plasma etching equipment and the etching method have the advantage that sidewall shapes can be improved for the formed etched holes.
Description
Technical field
The present invention relates to field of semiconductor manufacture, particularly a kind of plasma etching equipment and lithographic method.
Background technology
Along with the integrated level raising of semiconductor device, the live width of semiconductor device is more and more littler, and the control of critical size is also more and more important, and is also more and more higher to the requirement of etching technics.
Etching technics is that a kind of selectable removal is formed on the material of silicon chip surface or selectively removes the technology of silicon sheet material.Etching technics comprises wet etching and dry etching, and dry etching is owing to selectivity height, controllability become one of current the most frequently used etching technics by force.
Dry etching is plasma etching, feeds etching gas usually in plasma processing apparatus, and the described etching gas of ionization becomes plasma, utilizes described plasma that wafer to be etched is carried out etching.Existing method for etching plasma forms the photoresist figure at laminar surface to be etched usually, is that mask carries out etching to described layer to be etched with described photoresist figure.
Existing plasma processing apparatus comprises capacitance coupling plasma etching apparatus (Capacitor Coupled Plasma, CCP), inductively coupled plasma etching apparatus (Inductive Coupled Plasma, ICP), but, when adopting existing plasma processing apparatus to carry out etching technics, especially when the deep hole etching, low greater than the etching pattern fidelity (Profile) that formed in 10 o'clock such as the depth-to-width ratio (aspect ratio) of opening or the groove of etching, the sidewall torsion resistance of pattern is big.
Summary of the invention
The problem that the present invention solves is existing plasma processing apparatus when carrying out etching technics, and the etching pattern fidelity (Profile) of formation is low, and the sidewall torsion resistance of pattern is big.
For addressing the above problem, the invention provides a kind of plasma etching equipment, comprising: etching cavity; First radio-frequency power supply, described first radio-frequency power supply provides the radio-frequency power of 2MHz to 120MHz; Second radio-frequency power supply, described second radio-frequency power supply provides the radio-frequency power of 2MHz to 40MHz; Power supply pulse controller, described power supply pulse controller is controlled the pulse of first radio-frequency power supply and/or second radio-frequency power supply, make the pulse frequency of described first radio-frequency power supply greater than the pulse frequency of 1000Hz and/or described second radio-frequency power supply less than 1000Hz.
Optionally, the pulse frequency of described first radio-frequency power supply greater than 1000Hz less than the pulse frequency of 2.5KHz or described second radio-frequency power supply greater than 100Hz.
Optionally, the pulse frequency of described first radio-frequency power supply is at least 2 times of pulse frequency of described second radio-frequency power supply.
Optionally, described power supply pulse controller comprises the first radio-frequency power supply impulse controller and the second radio-frequency power supply impulse controller.
Optionally, the described first radio-frequency power supply impulse controller pulse duty factor of controlling described first radio-frequency power supply is 5%-95%.
Optionally, the described second radio-frequency power supply impulse controller pulse duty factor of controlling described second radio-frequency power supply is 5%-95%.
Optionally, the pulse mode of described first radio-frequency power supply is twin-stage pattern or single mode, and the described second radio-frequency power supply pulse mode is twin-stage pattern or single mode.
Optionally, described first radio-frequency power supply is the source radio-frequency power supply, the radio-frequency power of described first radio-frequency power supply output 13-120MHz; Described second radio-frequency power supply is the bias voltage radio-frequency power supply, the radio-frequency power of described second radio-frequency power supply output 2-13MHz.
Optionally, described plasma etching equipment is the capacitance coupling plasma etching apparatus, also comprise: first electrode and second electrode that are positioned at etching cavity, wherein said second electrode is relative with first electrode, described first radio-frequency power supply is electrically connected to first or second electrode, and described second radio-frequency power supply is electrically connected to second electrode.
Optionally, described plasma etching equipment is the inductively coupled plasma etching apparatus, also comprises: be positioned at electrode and the coil of etching cavity, wherein, described first radio-frequency power supply is electrically connected to coil, and described second radio-frequency power supply is electrically connected to electrode.
The present invention also provides a kind of lithographic method, comprising: wafer to be etched is provided; Adopt above-mentioned each plasma etching equipment that described wafer to be etched is carried out etching, form predetermined pattern at wafer to be etched.
Optionally, described predetermined pattern is through hole, opening or groove.
Optionally, the depth-to-width ratio of described predetermined pattern is greater than 10.
Compared with prior art, the present invention has the following advantages:
The present invention is by arranging power supply pulse controller, make win radio-frequency power supply and/or second radio-frequency power supply be output as impulse form, thereby can control the pulse of described first radio-frequency power supply and the pulse of second radio-frequency power supply independently, thereby can control the plasma temperature that is formed on etching cavity inside and plasma sheath (Plasma sheath) thickness ion incidence energy just independently.Embodiments of the invention have reduced in the plasma etch process; plasma is to the electron injury of wafer; need to prove especially; in high-aspect-ratio (high aspect ratio) pattern etching technology; particularly depth-to-width ratio was greater than 10 o'clock; embodiments of the invention can reduce the influence (side-effect) of positive charge oppose side wall in the plasma, preferably protect the sidewall of etching figure.
The lasting high-energy output of contrast prior art, the plasma density that pulse frequency is kept greater than first radio-frequency power supply of 1000Hz has high repetition frequency and low electron temperature, thereby can reduce plasma to the electron injury of wafer to be etched, pulse frequency has lower repetition rate less than described second radio-frequency power supply of 1000Hz with respect to described first radio-frequency power supply, can in and cation (Positive Ion) in the plasma of etching figure bottom, reduce the accumulation of sidewall cation effectively, thereby prevent etching pattern side wall torsional deformation.
In one embodiment, when the pulse frequency of independent control first radio-frequency power supply, the pulse frequency of first radio-frequency power supply is more low, plasma has the enough time to the electron injury of trenched side-wall generation, cause the trenched side-wall torsional deformation, and when the pulse frequency of described first radio-frequency power supply during greater than 1000Hz, can effectively reduce plasma to the electron injury that trenched side-wall produces, reduce the trenched side-wall torsional deformation.
In another embodiment, when the pulse frequency of independent control second radio-frequency power supply, the pulse frequency of second radio-frequency power supply is more high, causes trenched side-wall torsional deformation degree more big, and when the pulse frequency of described second radio-frequency power supply during less than 1000Hz, can reduce the trenched side-wall torsional deformation.
Description of drawings
Fig. 1 is the first radio-frequency power supply potential pulse and the second radio-frequency power supply potential pulse schematic diagram that power supply pulse controller is controlled first radio-frequency power supply and second radio-frequency power supply that pass through of one embodiment of the invention;
The ESEM comparison diagram of Fig. 2 etching wafer that is the present invention's first radio-frequency power supply when different two level pulse frequency;
Fig. 3 is the ESEM comparison diagram of first radio-frequency power supply etching wafer when different pulse frequencies in another embodiment of the present invention;
Fig. 4 is the ESEM comparison diagram of second radio-frequency power supply etching wafer when different pulse frequencies in another embodiment of the present invention.
Embodiment
Plasma etching feeds etching gas usually in plasma processing apparatus, and the described etching gas of ionization becomes plasma, utilizes described plasma that wafer to be etched is carried out etching.
Existing method for etching plasma forms mask pattern (comprising photoresist figure, hard mask pattern and hard mask pattern and photoresist storehouse figure) at laminar surface to be etched usually, is that mask carries out etching to described layer to be etched with the mask pattern.In etching through hole technology, the inventor finds in the process that adopts existing plasma etching equipment and technology etching dielectric layer, along with the increase of the depth-to-width ratio of the through hole (or opening or groove) that forms, the sidewall torsion resistance of the through hole of formation (or opening or groove) is big.
The inventor carries out creative research, etching pattern fidelity (Profile) the big reason of sidewall torsion resistance low, pattern is when finding to adopt existing plasma processing apparatus to carry out etching technics: sidewall has accumulated inhomogeneous electric charge in etching process, it is not vertical incidence that inhomogeneous electric charge accumulation can cause the plasma of incident, but is offset under the effect of sidewall non-uniform electric field.Finally cause the distortion of etching void shape.
Based on above-mentioned analysis, the present inventor provides a kind of plasma etching equipment, comprising: etching cavity; First radio-frequency power supply, described first radio-frequency power supply provides the radio-frequency power of 2MHz to 120MHz; Second radio-frequency power supply, described second radio-frequency power supply provides the radio-frequency power of 2MHz to 40MHz; Power supply pulse controller, described power supply pulse controller is controlled the pulse of first radio-frequency power supply and/or second radio-frequency power supply, make the pulse frequency of described first radio-frequency power supply greater than the pulse frequency of 1000Hz and/or described second radio-frequency power supply less than 1000Hz.
Particularly, the present inventor finds that the electric charge of etched hole sidewall uneven distribution can cause the skew of incident ion flight path, causes the etched hole distortion at last.Therefore correspondingly adopt described power supply pulse controller to control the pulse of first radio-frequency power supply and/or second radio-frequency power supply, make closing or low-power during the stage in pulse, concentration is extinguished or reduced to plasma cognition, and this moment, the electric charge in the accumulation of the high power stage of pulse can neutralize gradually.
Wherein said impulse controller can be that radio-frequency power supply is built-in, can be external also, need to prove, when described impulse controller was external, described first radio-frequency power supply and/or second radio-frequency power supply were suitable for receiving outside pulse signal.
Further, the present inventor finds, if causing electric charge not neutralize as yet, the too high meeting of pulse frequency just enters next step high power etch stages, so still can continue to cause the sidewall infringement, pulse frequency is too low then to have caused bigger infringement in the high power etch stages, so pulse frequency must be best in suitable numerical value effect, preferably, the scope of the pulse frequency of described first radio-frequency power supply is 1KHz-2.5KHz, the scope of the pulse frequency of described second radio-frequency power supply is 100Hz-1KHz, and described first radio-frequency power supply provides 60MHz, and when described second radio-frequency power supply provided 2MHz, the high power stage of the pulse charging neutrality effect of accumulation was good.
The present invention is by arranging power supply pulse controller, make win radio-frequency power supply and/or second radio-frequency power supply be output as impulse form, thereby can control pulse and the second radio-frequency power supply pulse of described first radio-frequency power supply independently, be formed on etching cavity internally plasma temperature and plasma sheath (Plasma sheath) thereby can control independently.Embodiments of the invention have reduced in the plasma etch process; plasma is to the electron injury of wafer; need to prove especially; in high-aspect-ratio (high aspect ratio) pattern etching technology; embodiments of the invention can reduce the influence (side-effect) of positive charge oppose side wall in the plasma, preferably protect the sidewall of etching figure.
The lasting high-energy output of contrast prior art, the plasma density that pulse frequency is kept greater than first radio-frequency power supply of 1000Hz has high repetition frequency and low electron temperature, thereby can reduce plasma to the electron injury of wafer to be etched, pulse frequency has lower repetition rate less than described second radio-frequency power supply of 1000Hz with respect to described first radio-frequency power supply, can in and cation (Positive Ion) in the plasma of etching figure bottom, reduce the accumulation of sidewall cation effectively, thereby prevent etching pattern side wall torsional deformation.
Below in conjunction with specific embodiment plasma etching equipment of the present invention is described in detail.
Embodiment one
The present inventor provides a kind of plasma etching equipment, comprising: etching cavity; First radio-frequency power supply, described first radio-frequency power supply provides the radio-frequency power supply of 2MHz to 120MHz; Second radio-frequency power supply, described second radio-frequency power supply provides the radio-frequency power supply of 2MHz to 40MHz; The power supply pulse controller that connects first radio-frequency power supply and second radio-frequency power supply, described power supply pulse controller is controlled the pulse of first radio-frequency power supply and second radio-frequency power supply, make the pulse frequency of described first radio-frequency power supply greater than the pulse frequency of 1000Hz and described second radio-frequency power supply less than 1000Hz.
Particularly, described plasma etching equipment can be capacitance coupling plasma etching apparatus or inductively coupled plasma etching apparatus.
Described first radio-frequency power supply is source radio-frequency power supply (Source RF Power), the radio-frequency power supply of the radio-frequency power supply of described first radio-frequency power supply output 2MHz to 120MHz radio-frequency power or the radio-frequency power of output 13-200MHz or be output as the radio-frequency power supply of 13MHz to 120MHz radio-frequency power.
Described second radio-frequency power supply is bias voltage radio-frequency power supply (Bias RF Power), the radio-frequency power supply of the radio-frequency power supply of described second radio-frequency power supply output 2MHz to 40MHz radio-frequency power or the radio-frequency power of output 2-13MHz.
In the present embodiment, described first radio-frequency power supply and second radio-frequency power supply are output as impulse form, particularly, and by power supply pulse controller is set, control described first radio-frequency power supply and second radio-frequency power supply, make described first radio-frequency power supply and second radio-frequency power supply be output as impulse form.
In one embodiment, described power supply pulse controller is controlled first radio-frequency power supply and second radio-frequency power supply simultaneously, makes win radio-frequency power supply and second radio-frequency power supply be output as impulse form.
Preferably, described power supply pulse controller is controlled the pulse of first radio-frequency power supply and second radio-frequency power supply, make the pulse frequency of described first radio-frequency power supply greater than the pulse frequency of 1000Hz and described second radio-frequency power supply less than 1000Hz.
In another embodiment, described power supply pulse controller comprises the first radio-frequency power supply impulse controller and the second radio-frequency power supply impulse controller, wherein, the described first radio-frequency power supply impulse controller is controlled the pulse parameter of described first radio-frequency power supply, frequency for example, duty ratio, voltage swing, the described second radio-frequency power supply impulse controller is controlled the pulse parameter of described second radio-frequency power supply, frequency for example, duty ratio, voltage swing, make that the pulse output of described first radio-frequency power supply and second radio-frequency power supply is separate, thereby make that plasma temperature and plasma sheath degree of regulation in the etching cavity are more flexible.
Preferably, the described first radio-frequency power supply impulse controller is controlled the pulse of described first radio-frequency power supply, make the pulse frequency of described first radio-frequency power supply greater than 1000Hz, the described second radio-frequency power supply impulse controller is controlled the pulse of described second radio-frequency power supply, makes the pulse frequency of described second radio-frequency power supply less than 1000Hz.
Need to prove that also the present inventor finds through research back, when the pulse frequency of described first radio-frequency power supply was at least 2 times of pulse frequency of described second radio-frequency power supply, the control effect of etching pattern side wall pattern was remarkable.
Further, when the pulse frequency of described first radio-frequency power supply greater than 1000Hz, when the pulse frequency of described second radio-frequency power supply is at least 2 times of pulse frequency of described second radio-frequency power supply less than the pulse frequency of 1000Hz and described first radio-frequency power supply, the plasma density that first radio-frequency power supply is kept has high repetition frequency and low electron temperature, thereby can reduce plasma to the electron injury of wafer to be etched, described second radio-frequency power supply has lower repetition rate with respect to described first radio-frequency power supply, can in and cation in the plasma of etching figure bottom, reduce the accumulation of sidewall cation effectively, thereby prevent etching pattern side wall torsional deformation.
In one embodiment, the present inventor finds, if causing electric charge not neutralize as yet, the too high meeting of pulse frequency just enters next step high power etch stages, so still can continue to cause the sidewall infringement, pulse frequency is too low then to have caused bigger infringement in the high power etch stages, so pulse frequency must be best in suitable numerical value effect, preferably, the scope of the pulse frequency of described first radio-frequency power supply is 1KHz-2.5KHz, the scope of the pulse frequency of described second radio-frequency power supply is 100Hz-1KHz, and described first radio-frequency power supply provides 60MHz, and when described second radio-frequency power supply provided 2MHz, the high power stage of the pulse charging neutrality effect of accumulation was good.
Please refer to Fig. 1, Fig. 1 is the first radio-frequency power supply potential pulse and the second radio-frequency power supply potential pulse schematic diagram that power supply pulse controller is controlled first radio-frequency power supply and second radio-frequency power supply that pass through of one embodiment of the invention, wherein, a among Fig. 1 is the first radio-frequency power supply potential pulse schematic diagram, and the b among Fig. 1 is the second radio-frequency power supply potential pulse schematic diagram; Pulse shown in the figure is (the switching) of two level types between high level and low level, the present invention also can be that ON-OFF type (switching between high level and zero) by the control first radio-frequency power supply potential pulse and the second radio-frequency power supply potential pulse, makes that plasma temperature and the plasma sheath degree of regulation in the etching cavity is more flexible.
Also need to prove, the present inventor finds, the pulse duty factor that the described first radio-frequency power supply impulse controller is controlled described first radio-frequency power supply is 5%-95%, when the pulse duty factor that the described second radio-frequency power supply impulse controller is controlled described second radio-frequency power supply is 5%-95%, can preferably reduce plasma to the electron injury of wafer to be etched.
Be that the capacitance coupling plasma etching apparatus is example with described plasma etching equipment below, article on plasma body etching apparatus elaborates.
The capacitance coupling plasma etching apparatus that present embodiment provides comprises: etching cavity; Be positioned at first electrode and second electrode of etching cavity, wherein said second electrode is relative with first electrode; Be connected to first radio-frequency power supply of first electrode, described first radio-frequency power supply provides the radio-frequency power supply of 2MHz to 120MHz; Be connected to second radio-frequency power supply of second electrode, described first radio-frequency power supply provides the radio-frequency power supply of 2MHz to 40MHz; The power supply pulse controller that connects first radio-frequency power supply and second radio-frequency power supply, described power supply pulse controller is controlled the pulse of first radio-frequency power supply and second radio-frequency power supply, make the pulse frequency of described first radio-frequency power supply greater than the pulse frequency of 1000Hz and described second radio-frequency power supply less than 1000Hz; The gas source that is communicated with etching cavity, described gas source are used for providing etching gas to etching cavity; The exhaust pump that is communicated with etching cavity, described exhaust pump are used for getting rid of the gas in the etching cavity.
When described capacitance coupling plasma etching apparatus carries out etching, wafer to be etched is positioned on the securing member in the etching cavity, described securing member is electrostatic chuck or mechanical fastening device.In one embodiment, described securing member is that first electrode or described securing member comprise first electrode.
Described gas source provides etching gas to etching cavity, and described wafer to be etched is carried out etching, and wherein in the etching process, described first radio-frequency power supply provides the radio-frequency power supply of 2MHz to 120MHz; Be connected to second radio-frequency power supply of second electrode, described first radio-frequency power supply provides the radio-frequency power supply of 2MHz to 40MHz, and described power supply pulse controller is controlled the pulse of first radio-frequency power supply and second radio-frequency power supply, make the pulse frequency of described first radio-frequency power supply greater than the pulse frequency of 1000Hz and described second radio-frequency power supply less than 1000Hz, until forming predetermined pattern at wafer to be etched.
Described predetermined pattern is through hole, opening or groove, and the depth-to-width ratio of described predetermined pattern is greater than 10.
The present inventor finds through experiment, the lithographic method that adopts present embodiment to provide, and wafer electron injury to be etched is little, and the predetermined pattern sidewall torsional deformation of formation is little.
Be that the inductively coupled plasma etching apparatus is example with described plasma etching equipment below, article on plasma body etching apparatus elaborates.
The inductively coupled plasma etching apparatus that present embodiment provides comprises:
Etching cavity; First radio-frequency power supply, described first radio-frequency power supply provides the radio-frequency power supply of 2MHz to 120MHz; Second radio-frequency power supply, described second radio-frequency power supply provides the radio-frequency power supply of 2MHz to 40MHz; Be positioned at electrode and the coil of etching cavity, wherein, described first radio-frequency power supply is electrically connected to coil, and described second radio-frequency power supply is electrically connected to electrode; The power supply pulse controller that connects first radio-frequency power supply and/or second radio-frequency power supply, described power supply pulse controller is controlled the pulse of first radio-frequency power supply and/or second radio-frequency power supply, make the pulse frequency of described first radio-frequency power supply greater than the pulse frequency of 1000Hz and/or described second radio-frequency power supply less than 1000Hz; The gas source that is communicated with etching cavity, described gas source are used for providing etching gas to etching cavity; The exhaust pump that is communicated with etching cavity, described exhaust pump are used for getting rid of the gas in the etching cavity.
When described inductively coupled plasma etching apparatus carries out etching, wafer to be etched is positioned on the securing member in the etching cavity, described securing member is electrostatic chuck or mechanical fastening device.In one embodiment, described securing member is that electrode or described securing member comprise electrode.
Described gas source provides etching gas to etching cavity, and described wafer to be etched is carried out etching, and wherein in the etching process, described first radio-frequency power supply provides the radio-frequency power supply of 2MHz to 120MHz; Be connected to second radio-frequency power supply of second electrode, described first radio-frequency power supply provides the radio-frequency power supply of 2MHz to 40MHz, and described power supply pulse controller is controlled the pulse of first radio-frequency power supply and second radio-frequency power supply, make the pulse frequency of described first radio-frequency power supply greater than the pulse frequency of 1000Hz and described second radio-frequency power supply less than 1000Hz, until forming predetermined pattern at wafer to be etched.
Particularly, described first radio-frequency power supply is source radio-frequency power supply (Source RF Power), the radio-frequency power supply of the radio-frequency power supply of described first radio-frequency power supply output 2MHz to 120MHz radio-frequency power or the radio-frequency power of output 13-200MHz or be output as the radio-frequency power supply of 13MHz to 120MHz radio-frequency power.
Described second radio-frequency power supply is bias voltage radio-frequency power supply (Bias RF Power), the radio-frequency power supply of the radio-frequency power supply of described second radio-frequency power supply output 2MHz to 40MHz radio-frequency power or the radio-frequency power of output 2-13MHz.
Described predetermined pattern is through hole, opening or groove, and the depth-to-width ratio of described predetermined pattern is greater than 10.
The present inventor finds through experiment, the lithographic method that adopts present embodiment to provide, and wafer electron injury to be etched is little, and the predetermined pattern sidewall torsional deformation of formation is little.
Embodiment two
The present inventor provides a kind of plasma etching equipment, comprising: etching cavity; First radio-frequency power supply, described first radio-frequency power supply provides the radio-frequency power supply of 2MHz to 120MHz; Second radio-frequency power supply, described second radio-frequency power supply provides the radio-frequency power supply of 2MHz to 40MHz; The power supply pulse controller that connects first radio-frequency power supply and second radio-frequency power supply, described power supply pulse controller are controlled the first radio-frequency power supply pulse, make the pulse frequency of described first radio-frequency power supply greater than 1000Hz.
Particularly, described plasma etching equipment can be capacitance coupling plasma etching apparatus or inductively coupled plasma etching apparatus.Described first radio-frequency power supply is source radio-frequency power supply (Source RF Power), the radio-frequency power supply of the radio-frequency power supply of described first radio-frequency power supply output 2MHz to 120MHz radio-frequency power or the radio-frequency power of output 13-200MHz or be output as the radio-frequency power supply of 13MHz to 120MHz radio-frequency power.Described second radio-frequency power supply is bias voltage radio-frequency power supply (Bias RF Power), the radio-frequency power supply of the radio-frequency power supply of described second radio-frequency power supply output 2MHz to 40MHz radio-frequency power or the radio-frequency power of output 2-13MHz.
In the present embodiment, described first radio-frequency power supply is output as impulse form, particularly, by power supply pulse controller is set, controls described first radio-frequency power supply, makes described first radio-frequency power supply be output as impulse form.
Preferably, described power supply pulse controller is controlled the pulse of described first radio-frequency power supply, makes the pulse frequency of described first radio-frequency power supply greater than 1000Hz.
In another embodiment, to control the pulse duty factor of described first radio-frequency power supply be 5%-95% to described power supply pulse controller.In another embodiment, the pulse mode of described first radio-frequency power supply is twin-stage (dual-level) pattern or single-stage (single-level) pattern.
Particularly, described plasma processing apparatus can be capacitance coupling plasma etching apparatus or inductively coupled plasma etching apparatus, and described plasma processing apparatus specifically describes the corresponding description that please refer among the embodiment one, here repeats no more.
Adopt the method for above-mentioned plasma processing apparatus etching wafer to comprise: wafer to be etched is provided; The using plasma etching apparatus carries out etching to described wafer to be etched, form predetermined pattern at wafer to be etched, wherein, described first radio-frequency power supply is source radio-frequency power supply (Source RF Power), the radio-frequency power supply of the radio-frequency power supply of described first radio-frequency power supply output 2MHz to 120MHz radio-frequency power or the radio-frequency power of output 13-200MHz or be output as the radio-frequency power supply of 13MHz to 120MHz radio-frequency power; Described second radio-frequency power supply is bias voltage radio-frequency power supply (Bias RF Power), the radio-frequency power supply of the radio-frequency power supply of described second radio-frequency power supply output 2MHz to 40MHz radio-frequency power or the radio-frequency power of output 2-13MHz; The power supply pulse controller that connects first radio-frequency power supply, described power supply pulse controller are controlled the first radio-frequency power supply pulse, make the pulse frequency of described first radio-frequency power supply greater than 1000Hz.
Please refer to Fig. 2, Fig. 2 is the ESEM comparison diagram of one embodiment of the invention etching wafer, etching condition is: first radio-frequency power supply provides the radio-frequency power supply of 60MHz, power output is switched for carry out pulse between 350 watts and 50 watts, second radio-frequency power supply provides the radio-frequency power supply of 2MHz, power output is 6500 watts, and etching cavity pressure is the 20-50 millitorr, and etching gas comprises: C
4F
6, C
4F
8, Ar, O
2And CH
2F
2, C wherein
4F
6Flow be 35 to 50SCCM, C
4F
8Flow be 35 to 50SCCM, the flow of Ar is 150 to 250SCCM, O
2Flow be 65 to 85SCCM, CH
2F
2Flow be 65 to 85SCCM, etch period is 400 seconds.
In the present embodiment, keep above-mentioned etching condition constant, adopt described power supply pulse controller to control the first radio-frequency power supply pulse, make that the pulse frequency of described first radio-frequency power supply is 1.8KHz and 200Hz, wafer is carried out etching groove, wherein, a among Fig. 2 is that the pulse frequency of first radio-frequency power supply is that 1.8KHz, frequency duty ratio are 82%, the pulse opening time that is described first radio-frequency power supply is 0.45 millisecond, the pulse shut-in time of described first radio-frequency power supply is 0.1 millisecond, carries out the sem photograph behind the etching groove; B among Fig. 2 is that the pulse frequency of first radio-frequency power supply is that 200Hz, frequency duty ratio are 80%, the pulse opening time that is described first radio-frequency power supply is 4 milliseconds, the pulse shut-in time of described first radio-frequency power supply is 1 millisecond, carry out the sem photograph behind the etching groove, obviously as can be seen, the trenched side-wall of a of Fig. 2 obviously sidewall torsional deformation than the b groove of Fig. 2 is little from Fig. 2.
The inventor is by above-mentioned creative experiment, when finding that pulse frequency when first radio-frequency power supply is more low, plasma has the enough time to the electron injury of trenched side-wall generation, cause the trenched side-wall torsional deformation, and when the pulse frequency of described first radio-frequency power supply during greater than 1000Hz, can effectively reduce plasma to the electron injury that trenched side-wall produces, reduce the trenched side-wall torsional deformation.
Please refer to Fig. 3, Fig. 3 is the ESEM comparison diagram of another embodiment of the present invention etching wafer, etching condition is: first radio-frequency power supply provides the radio-frequency power supply of 60MHz, power output is carried out pulse and is switched between 350 watts and 0 watt, second radio-frequency power supply provides the radio-frequency power supply of 2MHz, power output is 6500 watts, and etching cavity pressure is the 20-50 millitorr, and etching gas comprises: C
4F
6, C
4F
8, Ar, O
2And CH
2F
2, C wherein
4F
6Flow be 35 to 50SCCM, C
4F
8Flow be 35 to 50SCCM, the flow of Ar is 150 to 250SCCM, O
2Flow be 65 to 85SCCM, CH
2F
2Flow be 65 to 85SCCM, etch period is 345 seconds.
In the present embodiment, keep above-mentioned etching condition constant, adopt described power supply pulse controller to control the first radio-frequency power supply pulse, make the pulse frequency of described first radio-frequency power supply be respectively 1.8KHz, 1000Hz, the wafer of 500Hz, 200Hz carries out etching groove, wherein a among Fig. 3 is that the pulse frequency of first radio-frequency power supply is that 1.8KHz, frequency duty ratio are 82%, the pulse opening time that is described first radio-frequency power supply is 0.45 millisecond, the pulse shut-in time of first radio-frequency power supply is 0.1 millisecond, carries out the sem photograph behind the etching groove; Wherein the b among Fig. 3 is that the pulse frequency of first radio-frequency power supply is that 1000KHz, frequency duty ratio are 80%, the pulse opening time that is described first radio-frequency power supply is 0.8 millisecond, the pulse shut-in time of first radio-frequency power supply is 0.2 millisecond, carries out the sem photograph behind the etching groove; Wherein the c among Fig. 3 is that the pulse frequency of first radio-frequency power supply is that 500KHz, frequency duty ratio are 80%, the pulse opening time that is described first radio-frequency power supply is 1.6 milliseconds, the pulse shut-in time of first radio-frequency power supply is 0.4 millisecond, carries out the sem photograph behind the etching groove; Wherein the d among Fig. 3 is that the pulse frequency of first radio-frequency power supply is that 200KHz, frequency duty ratio are 80%, the pulse opening time that is described first radio-frequency power supply is 4 milliseconds, the pulse shut-in time of first radio-frequency power supply is 1 millisecond, carry out the sem photograph behind the etching groove, from sem photograph as can be seen, the ditch grooved profile that adopts present embodiment to form is impaired little.
Above-mentioned experiment is further verified: when the pulse frequency of first radio-frequency power supply is more low, plasma has the enough time to the electron injury of trenched side-wall generation, cause the trenched side-wall torsional deformation, and when the pulse frequency of described first radio-frequency power supply during greater than 1000Hz, can effectively reduce plasma to the electron injury that trenched side-wall produces, reduce the trenched side-wall torsional deformation.
Embodiment three
The present inventor provides a kind of plasma etching equipment, comprising: etching cavity; First radio-frequency power supply, described first radio-frequency power supply provides the radio-frequency power supply of 2MHz to 120MHz; Second radio-frequency power supply, described second radio-frequency power supply provides the radio-frequency power supply of 2MHz to 40MHz; The power supply pulse controller that connects second radio-frequency power supply, described power supply pulse controller is controlled the pulse of second radio-frequency power supply, makes the pulse frequency of described second radio-frequency power supply less than 1000Hz.
Particularly, described plasma etching equipment can be capacitance coupling plasma etching apparatus or inductively coupled plasma etching apparatus.Described first radio-frequency power supply is source radio-frequency power supply (Source RF Power), the radio-frequency power supply of the radio-frequency power supply of described first radio-frequency power supply output 2MHz to 120MHz radio-frequency power or the radio-frequency power of output 13-200MHz or be output as the radio-frequency power supply of 13MHz to 120MHz radio-frequency power.Described second radio-frequency power supply is bias voltage radio-frequency power supply (Bias RF Power), the radio-frequency power supply of the radio-frequency power supply of described second radio-frequency power supply output 2MHz to 40MHz radio-frequency power or the radio-frequency power of output 2-13MHz.
In the present embodiment, described second radio-frequency power supply is output as impulse form, particularly, by power supply pulse controller is set, controls described second radio-frequency power supply, makes described second radio-frequency power supply be output as impulse form.
Preferably, described power supply pulse controller is controlled the pulse of described second radio-frequency power supply, makes the pulse frequency of described second radio-frequency power supply less than 1000Hz.
Particularly, described plasma processing apparatus can be capacitance coupling plasma etching apparatus or inductively coupled plasma etching apparatus, and described plasma processing apparatus specifically describes the corresponding description that please refer among the embodiment one, here repeats no more.
Adopt the method for above-mentioned plasma processing apparatus etching wafer to comprise: wafer to be etched is provided; The using plasma etching apparatus carries out etching to described wafer to be etched, forms predetermined pattern at wafer to be etched, and wherein, described first radio-frequency power supply provides the radio-frequency power supply of 2MHz to 120MHz; Second radio-frequency power supply, described second radio-frequency power supply provides the radio-frequency power supply of 2MHz to 40MHz; The power supply pulse controller that connects second radio-frequency power supply, described power supply pulse controller are controlled the second radio-frequency power supply pulse, make the pulse frequency of described second radio-frequency power supply less than 1000Hz.
Please refer to Fig. 4, Fig. 4 is the ESEM comparison diagram of one embodiment of the invention etching wafer, etching condition is: first radio-frequency power supply provides the radio-frequency power supply of 60MHz, power output is 350 watts, second radio-frequency power supply provides the radio-frequency power supply of 2MHz, power output is switched for carry out pulse between 6500 watts and 0 watt, and etching cavity pressure is the 20-50 millitorr, and etching gas comprises: C
4F
6, C
4F
8, Ar, O
2And CH
2F
2, C wherein
4F
6Flow be 35 to 50SCCM, C
4F
8Flow be 35 to 50SCCM, the flow of Ar is 150 to 250SCCM, O
2Flow be 65 to 85SCCM, CH
2F
2Flow be 65 to 85SCCM, etch period is 400 seconds.
In the present embodiment, keep above-mentioned etching condition constant, adopt described power supply pulse controller to control the second radio-frequency power supply pulse, make the pulse frequency of described second radio-frequency power supply be respectively 1000KHz, 500Hz, 200Hz and second radio-frequency power supply carry out etching groove for continuing opening to wafer, wherein a among Fig. 4 is that the pulse frequency of second radio-frequency power supply is 1000Hz, the frequency duty ratio is 80%, the pulse opening time that is described second radio-frequency power supply is 0.8 millisecond, the pulse shut-in time of second radio-frequency power supply is 0.2 millisecond, carries out the sem photograph behind the etching groove; B among Fig. 4 is that the pulse frequency of second radio-frequency power supply is 500Hz, the frequency duty ratio is 80%, the pulse opening time that is described second radio-frequency power supply is 1.6 milliseconds, the pulse shut-in time of second radio-frequency power supply is 0.4 millisecond, carry out the sem photograph behind the etching groove, c among Fig. 4 is that the pulse frequency of second radio-frequency power supply is 200Hz, the frequency duty ratio is 80%, the pulse opening time that is described second radio-frequency power supply is 4 milliseconds, the pulse shut-in time of second radio-frequency power supply is 1 millisecond, carry out the sem photograph behind the etching groove, d among Fig. 4 is the sem photograph after etching groove is carried out in the lasting unlatching of second radio-frequency power supply, can see that from sem photograph the groove that continues unlatching second radio-frequency power supply is bigger than the trenched side-wall injury tolerance that adopts the present embodiment etching.
To sum up, the present invention is by arranging power supply pulse controller, make win radio-frequency power supply and/or second radio-frequency power supply be output as impulse form, thereby can control pulse and the second radio-frequency power supply pulse of described first radio-frequency power supply independently, be formed on etching cavity internally plasma temperature and plasma sheath (Plasma sheath) thereby can control independently.Embodiments of the invention have reduced in the plasma etch process; plasma is to the electron injury of wafer; need to prove especially; in high-aspect-ratio (high aspect ratio) pattern etching technology; embodiments of the invention can reduce the influence (side-effect) of positive charge oppose side wall in the plasma, preferably protect the sidewall of etching figure.
The lasting high-energy output of contrast prior art, the plasma density that pulse frequency is kept greater than first radio-frequency power supply of 1000Hz has high repetition frequency and low electron temperature, thereby can reduce plasma to the electron injury of wafer to be etched, pulse frequency has lower repetition rate less than described second radio-frequency power supply of 1000Hz with respect to described first radio-frequency power supply, can in and cation (Positive Ion) in the plasma of etching figure bottom, reduce the accumulation of sidewall cation effectively, thereby prevent etching pattern side wall torsional deformation.
In one embodiment, when the pulse frequency of independent control first radio-frequency power supply, the pulse frequency of first radio-frequency power supply is more low, plasma has the enough time to the electron injury of trenched side-wall generation, cause the trenched side-wall torsional deformation, and when the pulse frequency of described first radio-frequency power supply during greater than 1000Hz, can effectively reduce plasma to the electron injury that trenched side-wall produces, reduce the trenched side-wall torsional deformation.
In another embodiment, when the pulse frequency of independent control second radio-frequency power supply, the pulse frequency of second radio-frequency power supply is more high, causes trenched side-wall torsional deformation degree more big, and when the pulse frequency of described first radio-frequency power supply during less than 1000Hz, can reduce the trenched side-wall torsional deformation.
Though the present invention with preferred embodiment openly as above; but it is not to limit the present invention; any those skilled in the art without departing from the spirit and scope of the present invention; can utilize method and the technology contents of above-mentioned announcement that technical solution of the present invention is made possible change and modification; therefore; every content that does not break away from technical solution of the present invention; to any simple modification, equivalent variations and modification that above embodiment does, all belong to the protection range of technical solution of the present invention according to technical spirit of the present invention.
Claims (13)
1. a plasma etching equipment is characterized in that, comprising:
Etching cavity;
First radio-frequency power supply, described first radio-frequency power supply provides the radio-frequency power of 2MHz to 120MHz;
Second radio-frequency power supply, described second radio-frequency power supply provides the radio-frequency power of 2MHz to 40MHz;
Power supply pulse controller, described power supply pulse controller is controlled the pulse of first radio-frequency power supply and/or second radio-frequency power supply, make the pulse frequency of described first radio-frequency power supply greater than the pulse frequency of 1000Hz and/or described second radio-frequency power supply less than 1000Hz.
2. plasma etching equipment according to claim 1 is characterized in that, the pulse frequency of described first radio-frequency power supply greater than 1000Hz less than the pulse frequency of 2.5KHz or described second radio-frequency power supply greater than 100Hz.
3. plasma etching equipment according to claim 1 is characterized in that, the pulse frequency of described first radio-frequency power supply is at least 2 times of pulse frequency of described second radio-frequency power supply.
4. plasma etching equipment according to claim 1 is characterized in that described power supply pulse controller comprises the first radio-frequency power supply impulse controller and the second radio-frequency power supply impulse controller.
5. as plasma etching equipment as described in the claim 4, it is characterized in that the pulse duty factor that the described first radio-frequency power supply impulse controller is controlled described first radio-frequency power supply is 5%-95%.
6. as plasma etching equipment as described in the claim 4, it is characterized in that the pulse duty factor that the described second radio-frequency power supply impulse controller is controlled described second radio-frequency power supply is 5%-95%.
7. plasma etching equipment according to claim 1 is characterized in that the pulse mode of described first radio-frequency power supply is twin-stage pattern or single mode, and the described second radio-frequency power supply pulse mode is twin-stage pattern or single mode.
8. plasma etching equipment according to claim 1 is characterized in that described first radio-frequency power supply is the source radio-frequency power supply, the radio-frequency power of described first radio-frequency power supply output 13-120MHz; Described second radio-frequency power supply is the bias voltage radio-frequency power supply, the radio-frequency power of described second radio-frequency power supply output 2-13MHz.
9. plasma etching equipment according to claim 1, it is characterized in that, described plasma etching equipment is the capacitance coupling plasma etching apparatus, also comprise: first electrode and second electrode that are positioned at etching cavity, wherein said second electrode is relative with first electrode, described first radio-frequency power supply is electrically connected to first or second electrode, and described second radio-frequency power supply is electrically connected to second electrode.
10. plasma etching equipment according to claim 1, it is characterized in that, described plasma etching equipment is the inductively coupled plasma etching apparatus, also comprise: the electrode and the coil that are positioned at etching cavity, wherein, described first radio-frequency power supply is electrically connected to coil, and described second radio-frequency power supply is electrically connected to electrode.
11. a lithographic method is characterized in that, comprising:
Wafer to be etched is provided;
Adopt each plasma etching equipment of claim 1-10 that described wafer to be etched is carried out etching, form predetermined pattern at wafer to be etched.
12. lithographic method as claimed in claim 11 is characterized in that, described predetermined pattern is through hole, opening or groove.
13. lithographic method as claimed in claim 11 is characterized in that, the depth-to-width ratio of described predetermined pattern is greater than 10.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107295739A (en) * | 2016-04-12 | 2017-10-24 | 北京北方华创微电子装备有限公司 | Produce the method and its plasma apparatus of pulsed plasma |
| CN110739197A (en) * | 2018-07-18 | 2020-01-31 | 北京北方华创微电子装备有限公司 | Pulse signal control method and device, and plasma etching method and equipment |
| TWI815911B (en) * | 2018-06-22 | 2023-09-21 | 日商東京威力科創股份有限公司 | Plasma treatment method and plasma treatment device |
| TWI834156B (en) * | 2021-06-29 | 2024-03-01 | 大陸商中微半導體設備（上海）股份有限公司 | Plasma confinement ring, plasma processing equipment and method of processing semiconductors |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101369518A (en) * | 2007-03-21 | 2009-02-18 | 应用材料公司 | Plasma species and uniformity control through pulsed VHF operation |
| CN102737983A (en) * | 2012-07-05 | 2012-10-17 | 中微半导体设备(上海)有限公司 | Method for forming semiconductor structure |
| CN102983076A (en) * | 2011-09-07 | 2013-03-20 | 中国科学院微电子研究所 | Method for manufacturing semiconductor integrated circuit |
| CN103021783A (en) * | 2012-12-24 | 2013-04-03 | 中微半导体设备(上海)有限公司 | Etching method of semiconductor structure |
-
2013
- 2013-06-05 CN CN201310222055.2A patent/CN103295870B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101369518A (en) * | 2007-03-21 | 2009-02-18 | 应用材料公司 | Plasma species and uniformity control through pulsed VHF operation |
| CN102983076A (en) * | 2011-09-07 | 2013-03-20 | 中国科学院微电子研究所 | Method for manufacturing semiconductor integrated circuit |
| CN102737983A (en) * | 2012-07-05 | 2012-10-17 | 中微半导体设备(上海)有限公司 | Method for forming semiconductor structure |
| CN103021783A (en) * | 2012-12-24 | 2013-04-03 | 中微半导体设备(上海)有限公司 | Etching method of semiconductor structure |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107295739A (en) * | 2016-04-12 | 2017-10-24 | 北京北方华创微电子装备有限公司 | Produce the method and its plasma apparatus of pulsed plasma |
| TWI815911B (en) * | 2018-06-22 | 2023-09-21 | 日商東京威力科創股份有限公司 | Plasma treatment method and plasma treatment device |
| CN110739197A (en) * | 2018-07-18 | 2020-01-31 | 北京北方华创微电子装备有限公司 | Pulse signal control method and device, and plasma etching method and equipment |
| CN110739197B (en) * | 2018-07-18 | 2022-05-27 | 北京北方华创微电子装备有限公司 | Pulse signal control method and device, and plasma etching method and equipment |
| TWI834156B (en) * | 2021-06-29 | 2024-03-01 | 大陸商中微半導體設備（上海）股份有限公司 | Plasma confinement ring, plasma processing equipment and method of processing semiconductors |
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