JP2006108697A - Ion implantation method and device thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new resistless ion implantation method, capable of reducing the number of processes, particularly, in and around ion implantation process, for the purpose of reducing the manufacturing cost by the compression of the process for manufacturing a semiconductor device, and to provide a device for realizing this method. <P>SOLUTION: A resistless ion implantation method is provided, wherein the ions emitted from an ion source are passed through a mask that has an aperture having substantially analogous form to a required ion implanting region for forming a molded ion beam; and this ion beam is radiated to the required regions of a wafer that have not been subjected to application of resist for implanting the ions to the wafer; and by using this wafer, ions is implanted. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ion implantation method in a semiconductor process, and more particularly to an ion implantation method that does not require a resist process and an apparatus that realizes the ion implantation method.

  First, a conventional ion implantation process will be described.

  In a semiconductor device manufacturing process, an ion implantation method is used as a method for introducing impurities into a desired region of a semiconductor substrate. Ion implantation is performed by an ion implantation apparatus 20 as shown in FIG. The schematic structure is that an ion source 21 that generates dopant ions, a mass separator 23 that separates the emitted ions 22 into masses and sorts them into unnecessary ion beams 27 and 27 ′, an aperture 24 that passes the dopant ions 26, The lens 28 includes a lens 28 that converts the ion beam 26 into a parallel beam, a deflector 29 that scans the dopant ion beam 26 over the sample, a stage 31 that holds the wafer 30 that is the sample, and the like. As the ion source 21, a Freeman ion source, a microwave ion source, or the like that extracts ions by using a gas containing a dopant as plasma is used.

A conventional example of an ion implantation apparatus is described in the book “Ion Implantation Techniques” (Springer Series in Electrophysics 10, edited by Lysel, Grawishnigg, 1982) from page 3 to page 21. It can be found in a paper entitled “Ion Implantation System Concepts” written by Grawish Nigg. (Known example 1)
("Ion Implantation System Concepts" (Hans Glawischnig) ("Ion Implantation Techniques, (Springer Series in Electrophysics 10)" eds.H.Ryssel and H.Glawischnig, (1982) p.3-p.21.)
When ion implantation is performed in a desired region using such a conventional ion implantation apparatus, several steps are usually performed before and after ion implantation. That is, for example, a photoresist (hereinafter abbreviated as “resist”) is applied on a silicon wafer, an ion-implanted region pattern is exposed on the resist-coated wafer, and further development is performed to obtain a desired shape for ion implantation on the wafer In order to do so, the resist is removed. Thereafter, ion irradiation is performed, and dopant ions are implanted into the wafer in the region where the resist has been removed.
Next, the resist on the wafer is removed by ashing, and the wafer is washed to complete the ion implantation process.

  Thus, several steps are required in addition to the ion implantation step in order to implant ions into a desired region on the wafer. In addition, if this ion implantation process is performed a plurality of times during the entire process up to the completion of the device, such an accompanying process must be performed each time. This is because the ion beam used for conventional ion implantation is a uniform beam having a diameter of several centimeters or more, and therefore a resist mask is required to selectively implant ions at a desired location, and a pattern is formed on the resist accordingly. In addition, a process such as resist removal after ion implantation is required, and the above-described incidental processes are performed.

Pages 3-21 of "Ion Implantation Techniques" (Springer Series in Electrophysics 10, Lysel, Grawishnigg, 1982)

  As the performance of semiconductor devices increases, the processing dimensions on the devices become smaller and more complicated, and the processes for realizing them become more complicated, and the number of processes is increasing. For the semiconductor device manufacturer, how to reduce the cost of the device directly affects the profit, and therefore, the biggest challenge is to simplify the complicated process and reduce the manufacturing cost.

  The present invention aims to reduce the manufacturing cost by compressing the process steps of semiconductor device manufacturing, and in particular, the first object of the present invention is to provide a new ion implantation method that can reduce the steps before and after ion implantation, A second object is to provide an apparatus that realizes the first object.

In order to achieve the first object,
(1) In an ion implantation method in which the electrical properties of a sample are changed by introducing impurities, dopant ions emitted from an ion source are passed through a stencil mask having an opening substantially similar to a desired ion implantation region. An ion implantation method characterized by irradiating the sample with a shaped ion beam formed by an ion optical system that projects the aperture of the sample onto the sample;
(2) In the ion implantation method described in the above (1), an ion implantation method characterized by irradiating a sample whose surface is not coated with a photoresist with the shaped ion beam, and (3) mass of ions emitted from an ion source. Separately, only the dopant ions are selected, the dopant ions are passed through a stencil mask having an opening substantially similar to a desired ion implantation region to form a shaped ion beam, the ion beam is reduced by an ion optical system, and a photoresist is formed. An ion implantation method, wherein impurities are introduced into a substantially similar reduced region of the opening of the stencil mask by irradiating a desired region of a sample not coated with the ion beam,
(4) The ion implantation method according to any one of 1 to 3, wherein the shaped ion beam applied to the sample is stationary relative to the sample, particularly during ion implantation. Ion implantation method,
(5) In the ion implantation method according to any one of 1 to 4, in particular, the ion beam irradiated onto the sample is a plurality of parallel ion beam arrays at the time of ion implantation. Method,
(6) In the ion implantation method according to any one of 1 to 5, in particular, ions emitted from the ion source are mass-separated and only desired dopant ions are passed through the stencil mask to form a shaped ion beam. An ion implantation method characterized by:
(7) In the ion implantation method according to any one of 1 to 6, in particular, a shaped ion beam formed by passing through the stencil mask is reduced and projected onto the sample, and the opening shape of the stencil mask is formed on the sample. An ion implantation method characterized by performing ion implantation in a substantially similar reduced shape;
(8) In the ion implantation method according to any one of 1 to 7, in particular, the sample is silicon, and the ion species of the ion beam irradiated to the wafer is any of boron, phosphorus, and arsenic (9) The step using the ion implantation method according to any one of 1 to 8 above is an ion implantation step in a semiconductor device manufacturing process, An ion implantation method wherein the ion implantation amount is 1 × 10 ¹¹ or more and less than 1 × 10 ¹⁴ ions / cm ² ;
(10) The ion implantation method described in 9 above is an ion implantation method particularly for controlling the threshold voltage of the semiconductor device,
(11) The step using the ion implantation method according to any one of 1 to 10 above is an ion implantation step in a semiconductor device manufacturing process, and a photoresist that limits at least an ion implantation region on a semiconductor substrate in the preceding step An ion implantation method without a pattern formation process;
(12) In the ion implantation method according to any one of 1 to 11, the stencil mask has a plurality of ion implantation region patterns, and a desired ion implantation region pattern from the stencil mask according to desired ion implantation conditions. An ion implantation method characterized in that the energy or ion current amount of ions irradiated to the wafer is changed,
(13) In the ion implantation method according to any one of 1 to 11, the ion source emits a plurality of dopant ions, and the stencil mask has a plurality of ion implantation region patterns, and a desired ion implantation is performed. An ion implantation method characterized by selecting the ion implantation region pattern and irradiation ion species according to conditions, (14) a step using the ion implantation method described in any one of 1 to 13 above is a semiconductor device An ion implantation step in a manufacturing process, wherein the sample is a semiconductor wafer, and a single irradiation region of the ion beam to the wafer is n times (n: a positive integer) or 1 / an ion implantation method characterized by being m times (m: a positive integer);
(15) In the ion implantation method according to any one of 1 to 7, in particular, the sample is gallium arsenide, and the ion species of the ion beam irradiated to the sample is silicon, beryllium, magnesium, selenium. An ion implantation method characterized by being one of oxygen, sulfur, or
(16) In the ion implantation method described in any one of 1 to 15 above, the ion implantation method is particularly characterized in that the energy of the ion beam applied to the sample is 1 keV to 20 keV.

The second purpose is
(17) An ion source that emits dopant ions, at least two sets of Einzeln lenses that focus the ion beam, a mass separator that mass separates the ion beam, a mass separation aperture that allows only the dopant ions to pass, and a desired An ion implantation apparatus comprising a stencil mask having an opening substantially similar to the ion implantation region of the above, and a stage for holding a sample that does not cover the photoresist,
(18) An ion source for emitting dopant ions, a mass separator for mass-separating an ion beam, a stencil mask having an opening substantially similar to a desired ion implantation region, and ions emitted from the ion source for the stencil. An Einzeln lens that is incident on the mask, an Einzeln lens that focuses the shaped ion beam that has passed through the stencil mask, a mass separation aperture that allows only the dopant ion beam to pass through, and a sample that does not cover the photoresist. An ion implantation apparatus comprising a stage and a focusing lens that makes the shaped ion beam incident on the sample;
(19) An ion source that emits dopant ions, a mass separator that mass-separates ions emitted from the ion source, an Einzeln lens that focuses a mass-separated ion beam, the mass separator, and the stencil mask A stencil mask having an aperture substantially similar to a desired ion implantation region, an Einzeln lens for allowing the dopant ions to enter the stencil mask, and Ion implantation comprising an Einzeln lens that focuses the shaped ion beam that has passed through the stencil mask, a stage for holding a sample that does not cover the photoresist, and an Einzeln lens that allows the shaped ion beam to enter the sample vertically. apparatus,
(20) In the ion implantation apparatus described in any one of 17 to 19, the Einzeln lens that is incident on the stencil mask and the Einzeln lens that is incident on the sample with the shaped ion beam are the stencil. An ion implantation apparatus characterized by a positional relationship in which an image of a mask is projected onto the sample, and an applied voltage relationship;
(21) The ion implantation apparatus according to any one of (17) to (19), wherein the ion source is a duoplasmatron ion source or a liquid metal ion source,
(22) In the ion implantation apparatus as described in 21 above, in particular, the material to be ionized in the ion source is a gas or an alloy containing at least one of boron, arsenic, phosphorus, silicon, beryllium, and magnesium. An ion implanter,
(23) The ion implantation apparatus according to (17), wherein the mass separation aperture is installed at a crossover position of an Einzeln lens that focuses the shaped ion beam that has passed through the stencil mask. ,
(24) In the 19 ion implantation apparatus, in particular, the mass separation aperture is located at a crossover point of an Einzeln lens that mass-separates ions emitted from the ion source and focuses ions after mass separation. An ion implanter characterized by that,
(25) In the ion implantation apparatus according to any one of 17 to 19, in particular, the mass separation aperture is a thin plate having a plurality of holes with different openings, and the position fine adjustment mechanism and the hole selection mechanism An ion implantation apparatus characterized by comprising:
(26) The ion implantation apparatus according to any one of (17) to (19), wherein the stage is capable of fine movement along the ion optical axis, (27) Any of the above-described 17 to 19 In such an ion implantation apparatus, the mass separator is, in particular, a fan-shaped magnet,
(28) The ion implanter according to any one of 17 to 19, wherein the mass separator is, in particular, a Wien filter in which a magnetic pole and an electrode are orthogonal to each other,
(29) In the ion implantation apparatus according to any one of 17 to 19, in particular, a ratio of acceleration energy of ions irradiated to the sample with respect to initial energy with respect to emitted ions is 1.0 to 3.0. Ion implanter,
(30) In the ion implantation apparatus of any one of 17 to 19, a vacuum shutoff valve is further provided immediately below the crossover position of the Einzeln lens that focuses the shaped ion beam that has passed through the stencil mask. An ion implanter characterized by
(31) In the ion implantation apparatus according to any one of 17 to 19, the ion beam blocking shutter is further provided immediately below the crossover position of the Einzeln lens for focusing the shaped ion beam that has passed through the stencil mask. An ion implanter characterized by that,
(32) In the 19 ion implantation apparatus, further, a shutter for blocking an ion beam immediately below a crossover point of an Einzeln lens for mass-separating emitted ions from the ion source and focusing the ions after mass separation. An ion implanter characterized by the installation of
(33) In the above 17 ion implantation apparatus, the stencil mask has a plurality of patterns subjected to ion irradiation on the stencil mask, has an exchange mechanism in a vacuum vessel, and selects an irradiation pattern from outside the vacuum. An ion implanter characterized by having a stencil mask controller for
(34) In the ion implantation apparatus according to any one of 17 to 19, in particular, the stencil mask has a plurality of patterns subjected to ion irradiation on the stencil mask, has an exchange mechanism in a vacuum vessel, and has an ion An ion implantation apparatus comprising a control device for selecting a pattern on a source and a stencil mask and adjusting at least one of irradiation ion current and energy;
(35) In the above 17 ion implantation apparatus, the ion source is a plurality of ion sources that emit different kinds of dopant ions. (36) In the above 32 ion implantation apparatus, The stencil mask has a plurality of types of patterns that are subjected to ion irradiation on the stencil mask, has an exchange mechanism in the vacuum vessel, selects the pattern on the ion source and the stencil mask, and increases the strength of the mass separator. An ion implanter characterized by having a control device for adjusting;
(37) In the ion implantation apparatus of any one of 17 to 36, in particular, the sample is silicon, and the shaped ion beam that reaches the sample is any one of boron, phosphorus, and arsenic, and An ion implantation apparatus characterized by forming a beam having an ultimate ion current of 0.1 μA or more and a region irradiated at a time of 1 cm ² or more;
(38) A plurality of chambers for performing steps in the semiconductor manufacturing process, a wafer handler for loading / unloading wafers between them, and a wafer handler housing connected to the plurality of chambers for storing the wafer handlers. In the multi-chamber process apparatus, at least one of the chambers is the ion implantation apparatus described in any one of 17 to 24 above. Also,
(39) A semiconductor using any one of the ion implantation method according to any one of 1 to 15 above, the ion implantation apparatus according to any one of 16 to 29 above, and the multi-chamber process device according to 38 above. A device and a system using the device can be manufactured.

  The resistless ion implantation method and apparatus according to the present invention provide the following effects.

(1) Resist application, exposure, development, conventional ion implantation, and ashing steps are reduced. Along with this, personnel costs, operating costs, and maintenance costs for the personnel in charge of these devices are reduced, and furthermore, by replacing these devices with the resistless ion implantation apparatus according to the present invention, the occupied floor area of the semiconductor manufacturing apparatus is reduced. Reduced. By comprehensively evaluating these and using the resistless ion implantation method according to the present invention, the manufacturing cost of the device could be reduced.

(2) The ion implantation method according to the present invention does not require a resist, eliminates the wet process of resist coating, and can dry the processes before and after the ion implantation. Thereby, it can attach to the multi-chamber process apparatus which connected many manufacturing apparatuses.

(3) Since resist coating, exposure, development, conventional ion implantation, ashing, and the like are reduced, the process is stable without being affected by the ambient atmosphere in which the wafer is affected by the passage of each device. This makes it possible to create a homogeneous device.

(4) Since the steps before and after ion implantation are reduced as described in (1) above, the wafer transfer operation between the steps is reduced. As a result, the risk of foreign matter adhering to the carrier during transport is reduced, and the yield of device manufacturing is improved.

  In FIG. 1, the ion source 2 emits dopant ions. For example, when the sample to be ion-implanted is Si, boron (B), phosphorus (P), and arsenic (As) are emitted, and at least one of these elements is released. The type of ion source depends on the ion optical system downstream of the ion source, but a point light source is required to project the mask aperture sharply on the wafer, and a duo with a liquid metal ion source and a micro light source is required. A plasmatron ion source can be used.

  The mass separator 3 is for separating ions used for ion implantation and other ions out of ions emitted from the ion source. By using a mass separator in which an electrode called a Wien filter and magnetic poles are installed orthogonally, a desired ion beam can be passed on the optical axis.

The mask 9 is a stencil mask having an opening substantially similar to a desired ion implantation region. The stencil mask is made of a Si substrate. For example, Nakayama et al., In the Journal of Vacuum Science and Technology, Vol. B6 (1990), pages 1836 to 1840, “Electron Beam Cell Projection Lithography: A New High Throughput Electron Beam Direct Writing Technology Using a Special Tailored Silicon Aperture. (Known example 2)
(Y. Nakayama et al. "Electron-beam cell projection lithography: A new high-throughput electron-beam direct-writing technology using a specially tailored Si aperture", J. Vac. Sci. Technol. B6 (1990) 1836-1840 )
The stencil mask shown here is used for electron beam lithography, but can also be applied to this ion implantation method. The opening provided in the stencil mask is determined by the size of the ion implantation region and the reduction ratio. At this time, the minimum opening dimension is determined by the minimum dimension of the desired ion implantation region and the maximum aspect ratio that can be created by dry etching. For example, in order to create a rectangular area of 2 μm square with an optical system with a reduction ratio of 1/5, a rectangular opening of 10 μm square may be provided on the stencil mask. If the aspect ratio at which an opening with good perpendicularity can be opened by dry etching is 5, the thickness of the stencil mask can be set to 50 μm. Further, since the thickness is sufficiently large, such as several tens of μm, it can sufficiently withstand thinning by ion irradiation.

  The converging lens 8 is an electrostatic electrode group for converging a broad ion beam, and the electrode configuration and applied voltage can have various changes depending on the beam converging condition. The focusing lenses 12 and 19 and the projection lens 14 are also Einzern type lenses.

  Hereinafter, the details of an ion implantation method and apparatus according to the present invention will be described based on embodiments shown in the drawings.

Example 1
First, the schematic configuration of the ion implantation apparatus will be described with reference to FIG. In FIG. 1, 1 is an ion implantation apparatus according to the present invention, 2 is an ion source, and in this embodiment, the ion source 2 is a liquid metal ion source that emits boron ions that are dopants for Si. The material to be ionized in the ion source 2 is a ternary alloy of nickel / boron / silicon. A mass separator 3 sorts out the released ions 4 into desired dopant ions 5 (boron monovalent ions in this embodiment) and unnecessary ions 6. Reference numeral 7 denotes a mass separation aperture for allowing only dopant ions to pass therethrough and not sending unnecessary ions 6 downstream. Since the mass separation aperture 7 is installed on the upstream side of the mask 9, unnecessary ions 6 do not irradiate the mask, and the wear of the mask 9 is reduced and the durability is increased.

  Reference numeral 8 denotes a focusing lens that bends the trajectory so that ions that pass through the mass separation aperture 7 and are incident on the mask 9 substantially perpendicularly. In the figure, although it is schematically shown as an ellipse, it is actually an Einzeln lens composed of three or more electrodes. The mask 9 held by the conductive mask holder 10 is a stencil mask having an opening substantially similar to a desired ion implantation region. In this embodiment, an opening is provided in a silicon wafer by a conventional dry process. The shaped ion beam 11 by dopant ions obtained through the mask 9 is focused by the focusing lens 12, passes through the aperture 13, and is incident on the sample 15 by the projection lens 14 substantially perpendicularly. The sample 15 is a silicon wafer held on the stage 16, and the resist used in conventional ion implantation is not applied to the surface. The stage 16 can be finely moved with a laser interferometer, and can be accurately moved stepwise from one ion implantation region to the next region. Reference numeral 17 denotes a vacuum container.

  In this example, the outermost frame of the ion implantation region on the sample was about 10 mm square, and the reached ion current at this time was 0.1 μA. In FIG. 1, the aperture on the mask 9 is reduced by the focusing lens 12 and the projection lens 14 to irradiate the sample. With such a configuration, by expanding the shape of the desired ion implantation region or opening the same size on the mask 9, it is possible to ion-implant the sample 15 in a reduced size or the same size. it can.

  The ion implantation apparatus 1 having such a configuration has the following characteristics. As shown in FIG. 3A, in the conventional ion implantation method, a resist 42 formed by irradiating a wafer 42 coated with a resist 41 in close contact with a large-diameter ion beam 40 of a dopant and making full use of lithography technology. Ion implantation is performed using the openings 43 and 43 ′ of 41. Reference numeral 44 denotes an ion-implanted region. The arrows on both sides of the ion beam 40 indicate that the ion beam is ion-implanted while being deflected. On the other hand, in the ion implantation method according to the present invention, as shown in FIG. 3B, when the wafer 41 is irradiated with ions, the ion beam is shaped into the shape of the ion implantation region. There is no need and direct ion implantation can be performed. In order to obtain this shaped ion beam, an opening substantially similar to the desired ion implantation area is provided in the mask, and the ratio of the size of the opening in the mask and the ion implantation area on the wafer is set between the mask and the wafer. Depending on the arrangement of the ion optical system and the applied voltage, the ion optical system may be set in accordance with a desired ion magnification.

  When ion implantation for one region is completed, the ion beam is brought into a blanking state (a blanking electrode is not shown), or a shutter (18, FIG. 1) provided at any position between the wafer and the ion source. 18 '). In this state, the stage 16 is moved to the next ion implantation location. After the stage has been moved to a predetermined position, the blanking state is released or the shutter is released, the shaped ion beam 11 reaches the sample, and ions can be implanted in the next region. By repeating this operation, the entire sample can be ion-implanted.

  FIG. 1 is completely different from the conventional ion implantation apparatus (FIG. 2) in that an ion beam to be irradiated with ions is formed by a mask. In FIG. 1, the ion beam for irradiating the sample is a shaped beam that forms the shape of an ion implantation region, and a conventional resist is unnecessary. Accordingly, the steps related to the resist, that is, the steps of coating, exposing, developing, and ashing can be reduced. Also, the ion optical system is completely different on the apparatus surface, and a mask holder for holding a stencil mask is newly installed. On the other hand, the ion implantation apparatus of the present invention is different from the conventional apparatus in that the beam deflector 19 shown in FIG.

  There is also an ion projection lithography apparatus as a related conventional apparatus. For example, it is described in a paper entitled “Progress in Ion Projection Lithography” by A. Chalpka et al., Described in the collection of papers “Microelectronic Engineering”, Vol. 17, (1992) pp. 229-240. ing. (Known example 3) (A.Chalupka et al. "Progress in Ion Projection Lithography", Microelectronic Engineering 17 (1992) 229-240.) This is a pattern of ionized light elements such as helium and hydrogen. The resist is applied to the wafer by applying a beam to the resist-coated wafer. Compared to exposure with electrons, ion exposure has the advantage that the irradiation effect is small because the scattering in the resist is small, and the irradiated region can be transferred.

  However, this ion projection lithography apparatus differs from the ion implantation apparatus according to the present invention in the following points.

(1) Ion species are light element gas species, hydrogen and helium.

(2) The ion beam irradiation is performed on a sample having a resist on the surface, and is an apparatus that performs ion exposure on the resist.

(3) Since the aperture for performing substantial mass separation of the emitted ions is on the downstream side of the stencil mask, almost all of the emitted ions irradiate the stencil mask.

(Example 2)
As an embodiment of the ion implantation method according to the present invention, an ion implantation process in a semiconductor process will be described.

The ion implantation method according to the present invention was applied to the manufacture of a 4 megabit dynamic access memory. In the ion implantation process, the present invention is applied particularly to the threshold voltage control in the memory cell and the peripheral circuit and the well formation of the peripheral circuit. A pattern for each process is created on the stencil mask, and the mask pattern is exchanged for each process.
However, since all the patterns are installed on the mask, the mask pattern can be exchanged instantaneously. At this time, exchange of the mask pattern, setting of the ion implantation amount, start and end of ion implantation, etc. are all performed by computer control.

For example, in an ion implantation process for controlling a threshold voltage of a peripheral circuit of a memory cell, a region in which a rectangle of about 2 × 2 (μm) to 30 × 30 (μm) is scattered on a wafer not coated with a resist. Then, boron (B) ions were implanted at 5 × 10 ¹² (pieces / cm ² ) at an incident energy of 10 keV. In the ion implantation process, a series of lithography processes such as resist coating, exposure, development, and removal of the resist after ion implantation, which have been performed prior to the ion implantation process, can be performed in this method without performing the above-described lithography. When combined with the total ion implantation process, time and economy were saved.

(Example 3)
As shown in FIG. 4, the third embodiment is an example in which one set of lenses is reduced compared to the first embodiment and three Einzeln lenses 104, 106, and 113 are configured.
The mask, stage, etc. are the same as in the first embodiment.

In FIG. 4, an ion source 100 is a liquid metal ion source that emits phosphorus ions that are dopants for Si. The emission angle current density (current density per unit solid angle) of the monovalent phosphorus ions emitted from this ion source is 5 μA / sr when the total emission ion current is 1 μA, and the spread of the emitted ions is 10 ° (half-open angle). ). The ion beam collimated by the lens 113 is perpendicularly incident on the mask 103. The irradiation area at this time was allowed to pass through the mask pattern while being restricted to an area of 5 ° which is half the opening angle by the beam limiting aperture 101 in consideration of the angular distribution of the emitted ion current.
The reduction ratio of the mask pattern 103 (rectangular with a side of 16 mm) by the irradiation lens 104 and the lens 106 to the mask is 1/2. Both the lens 104 and the lens 106 are Einzeln lenses. At this time, a rectangular pattern beam of 8 mm on a side with a current density of 0.1 μA / cm ² arrives on the wafer 107 to which no resist is applied. When the ion implantation amount (dose) is set to 1 × 10 ¹² (pieces / cm ² ), the ion implantation time ends in about 1.6 seconds. The energy of the irradiated ions is 10 keV, which is ion implantation into a shallow region. When ion implantation with the patterned ion beam 108 was continued on the wafer 107 having a diameter of 8 inches, one wafer was completed in about 460 shots, and a production rate (throughput) of about 17 sheets per hour was exhibited. In the conventional process, the throughput is approximately 4 sheets / hour for a series of processes from resist application, exposure with a stepper, development, conventional ion implantation, resist removal by ashing, and water washing, so the throughput is improved by about 4 times. Achieved.

  In this apparatus, the mass separator 102 was installed immediately after the ion source 101, the mass separation diaphragm 105 was installed at the crossover point of the lens 106, and unnecessary ions 109 emitted from the ion source were removed. A gate valve 110 is further installed at the position of the mass separation diaphragm 105 so that the vacuum between the sample chamber 111 and the ion optical system chamber 112 in which the lens 104 and the mask 103 are installed can be separated. Thereby, it has the effect which can reduce the deterioration of the vacuum which arises at the time of replacement | exchange of a sample.

Example 4
The present embodiment is an example in which the ion implantation apparatus shown in the first embodiment is coupled to one chamber of a multi-chamber process apparatus as shown in FIG. In this multi-chamber process apparatus, process chambers 150, 151, 152 and load lock chambers 153A, 153B are provided with a wafer handler 154 and gate valves 157A, 157B, 157C, a transfer chamber 156 for transferring the wafer 55 to the respective chambers. With a device coupled through 157D and 157E, a plurality of continuous processes can be processed basically without exposing the wafer to the atmosphere.

The chamber 150 in FIG. 5 is an ion implantation apparatus according to the present invention, the chamber 151 is a secondary ion mass spectrometer, and the chamber 152 is a scanning electron microscope.
Of course, these chambers are not limited to these devices. The wafer 158 introduced into the load lock chamber 153A is introduced into the transfer chamber 156 by the wafer handler 154 after the gate valve 157E is opened. After the gate valve 157E is closed, the gate valve 157A is opened, and the wafer 158 is placed on the stage of the ion implantation apparatus 159 according to the present invention. Thereafter, the gate valve 157A is closed and evacuated to a predetermined degree of vacuum. However, since each chamber is in an ultrahigh vacuum state, the exhaust of the stage in the ion implantation apparatus is in an ultrahigh vacuum state in a short time. In this state, ion implantation by the shaped ion beam is started. This step is completed when ions are implanted over the entire wafer under predetermined ion implantation conditions. Wafer 158 is moved from chamber 150 to chamber 151. The opening and closing of the gate valve during this time is the same as described above. The test device on the wafer 158 can be analyzed by the secondary ion mass spectrometer 160 in the chamber 151 to check whether a predetermined ion implantation condition is satisfied. Further, the wafer 158 is moved to the chamber 152 and the wafer surface is observed to confirm that there is no abnormality. By such a process, ion implantation can be performed reliably in a short time and without being exposed to the atmosphere.

  As described above, since the ion implantation apparatus according to the present invention does not require a resist, the wet process of resist coating and cleaning is eliminated, and the film is completely dried and can be connected to other semiconductor manufacturing apparatuses and analysis apparatuses for dry processes. . As a result, the manufacture of the semiconductor device becomes efficient and the yield is improved.

It is a schematic block diagram for demonstrating one Example of the ion implantation apparatus by this invention. It is a schematic block diagram of the ion implantation apparatus used conventionally. (A) It is a figure for clearly showing a comparison between a situation where ions are implanted into a desired region by a conventional ion implantation apparatus and a situation where (b) ion implantation is performed by a resistless ion implantation apparatus according to the present invention. is there. It is a schematic block diagram for demonstrating another Example of the ion implantation apparatus by this invention. It is a schematic block diagram for demonstrating the example applied to the multi-chamber process apparatus in another Example of the ion implantation apparatus by this invention especially.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Ion implantation apparatus, 2 ... Ion source, 3 ... Mass separator, 4 ... Emitted ion, 5 ... Dopant ion, 6 ... Unwanted ion, 7 ... Aperture, 8, 19 ... Focusing lens, 9 ... Mask, 10 ... Mask Holder ... 11 Shaped ion beam 12 ... Focusing lens 13 ... Aperture 14 ... Projection lens 15 ... Sample 16 ... Stage 17 ... Vacuum container 18, 18 '... Shutter 20 ... Ion implanter 21 ... Ion source, 22 ... emitted ions, 23 ... mass separator, 24 ... aperture, 26 ... dopant ion beam, 27, 27 '... unwanted ions, 28 ... lens, 29 ... deflector, 30 ... sample, 31 ... stage, 40 ... Ion beam, 41 ... Resist, 42 ... Wafer, 43 ... Ion implantation region (opening), 44 ... Ion implantation region, 45, 45 '... Ion implantation region, 46,46' ... Forming ion On-beam, 100 ... ion source, 101 ... beam limiting aperture, 102 ... mass separator, 103 ... focusing lens, 104 ... focusing lens, 105 ... mass separation diaphragm, 106 ... focusing lens, 107 ... sample (wafer), 108 ... molding Pattern ion beam, 109 ... unwanted ions, 110 ... gate valve, 111 ... sample chamber, 112 ... ion optical system chamber, 150, 151, 152 ... chamber, 153A, 153B ... load lock chamber, 154 ... wafer handler, 155, 158 DESCRIPTION OF SYMBOLS 158 '... Wafer, 156 ... Transfer chamber, 157A, 157B, 157C, 157D, 157E ... Gate valve, 159 ... Ion implanter, 160 ... Secondary ion mass spectrometer.

Claims (39)

  In the ion implantation method, dopant ions emitted from an ion source are formed by an ion optical system that passes through a stencil mask having an opening substantially similar to a desired ion implantation region and projects the opening on the mask onto a sample. An ion implantation method characterized by irradiating the sample with a shaped ion beam.   2. An ion implantation method according to claim 1, wherein said molded ion beam is irradiated to a sample whose surface is not coated with a photoresist.   The ions emitted from the ion source are mass-separated to select only dopant ions, and the dopant ions are passed through a stencil mask having an opening substantially similar to a desired ion implantation region to form a shaped ion beam. The ion beam is reduced by the step of irradiating a desired region of a sample not coated with a photoresist with the shaped ion beam, thereby introducing impurities into a substantially similar reduced region of the opening of the stencil mask. Ion implantation method.   4. The ion implantation method according to claim 1, wherein the ion beam applied to the sample is stationary relative to the sample, particularly during ion implantation. Injection method.   5. The ion implantation method according to claim 1, wherein the ion beam applied to the sample is a plurality of parallel ion beam arrays, particularly during ion implantation.   6. The ion implantation method according to claim 1, wherein in particular, ions emitted from the ion source are mass-separated and only desired dopant ions are passed through the stencil mask to form a shaped ion beam. An ion implantation method characterized by the above.   7. The ion implantation method according to claim 1, wherein in particular, a shaped ion beam formed by passing through the stencil mask is reduced and projected onto a sample, and substantially similar to the opening shape of the stencil mask on the sample. Ion implantation method, characterized in that ion implantation is performed in a reduced size.   8. The ion implantation method according to claim 1, wherein, in particular, the sample is silicon, and the ion species of the ion beam irradiated to the wafer is any one of boron, phosphorus, and arsenic. There is provided an ion implantation method. The step using the ion implantation method according to claim 1 is an ion implantation step in a semiconductor device manufacturing process, and an ion implantation amount to the sample is 1 × 10 ¹¹ or more, 1 × 10 ^14. An ion implantation method characterized in that the number of ions is less than 1 / cm ² .   10. The ion implantation method according to claim 9, wherein the ion implantation method is an ion implantation for controlling a threshold voltage of the semiconductor device.   A process using the ion implantation method according to claim 1 is an ion implantation process in a semiconductor device manufacturing process, and a photoresist pattern for limiting an ion implantation region on at least a semiconductor substrate in the preceding process. Ion implantation method without forming process.   12. The ion implantation method according to claim 1, wherein the stencil mask has a plurality of ion implantation region patterns, and a desired ion implantation region pattern is selected from the stencil mask according to desired ion implantation conditions. And changing the energy or ion current amount of ions irradiated to the wafer.   12. The ion implantation method according to claim 1, wherein the ion source emits a plurality of dopant ions, and the stencil mask has a plurality of ion implantation region patterns to satisfy desired ion implantation conditions. An ion implantation method characterized by selecting the ion implantation region pattern and selecting an irradiation ion species.   The step using the ion implantation method according to claim 1 is an ion implantation step in a semiconductor device manufacturing process, wherein the sample is a semiconductor wafer, and a single ion beam is applied to the wafer. An ion implantation method, wherein the irradiation region is n times (n: positive integer) or 1 / m times (m: positive integer) of one device chip region.   8. The ion implantation method according to claim 1, wherein, in particular, the sample is gallium arsenide, and the ion species of the ion beam irradiated on the sample is silicon, beryllium, magnesium, selenium, oxygen An ion implantation method characterized by being one of sulfur and sulfur.   16. The ion implantation method according to claim 1, wherein the ion beam energy applied to the sample is in the range of 1 keV to 20 keV.   A stencil mask having an ion source for emitting dopant ions, at least two sets of Einzeln lenses for focusing the ion beam, a mass separator for mass-separating the ion beam, and an opening substantially similar to a desired ion implantation region And an ion implantation apparatus comprising a mass separation aperture that allows only dopant ions to pass through, and a stage for holding a sample that does not cover the photoresist.   An ion source that emits dopant ions; a mass separator that mass separates the ion beam; a stencil mask having an opening substantially similar to a desired ion implantation region; and a dopant ion between the mass separator and the stencil mask. A mass separation aperture that allows only the beam to pass through, an Einzeln lens that allows the dopant ions to enter the stencil mask, an Einzeln lens that focuses the shaped ion beam that has passed through the stencil mask, and a sample that does not cover the photoresist. An ion implantation apparatus comprising a stage for holding and a focusing lens for allowing the shaped ion beam to enter the sample.   An ion source that emits dopant ions, a mass separator that mass-separates ions emitted from the ion source, an Einzeln lens that focuses the ion beam that has been mass-separated, and a mass separation aperture that allows only the dopant ion beam to pass through A stencil mask having an opening substantially similar to a desired ion implantation region, an Einzeln lens that is incident on the stencil mask surface, an Einzeln lens that focuses a shaped ion beam that has passed through the stencil mask, and a photoresist. An ion implantation apparatus comprising a stage for holding a sample that does not cover the sample and a lens that causes the shaped ion beam to enter the sample.   The ion implantation apparatus according to any one of claims 17 to 19, wherein the Einzeln lens that is incident on the stencil mask and the Einzeln lens that is incident on the sample with the shaped ion beam are the stencil mask. An ion implantation apparatus characterized in that a reduced image has a positional relationship and an applied voltage relationship projected onto the sample.   20. The ion implantation apparatus according to claim 17, wherein the ion source is a duoplasmatron ion source or a liquid metal ion source.   The ion implantation apparatus according to claim 21, wherein the material to be ionized in the ion source is a gas or an alloy containing at least one of boron, arsenic, phosphorus, silicon, beryllium, and magnesium. Ion implanter.   19. The ion implantation apparatus according to claim 18, wherein the mass separation aperture is installed at a crossover position of an Einzeln lens that focuses the shaped ion beam that has passed through the stencil mask.   20. The ion implantation apparatus according to claim 19, in particular, the mass separation aperture is located at a crossover point of an Einzeln lens that mass-separates ions emitted from the ion source and focuses the ions after mass separation. An ion implantation apparatus.   The ion implantation apparatus according to any one of claims 17 to 19, in particular, the mass separation aperture is a thin plate having a plurality of holes having different openings, and a fine position adjustment mechanism for the holes and a selection mechanism for the holes. An ion implantation apparatus comprising:   20. The ion implantation apparatus according to claim 17, wherein the stage can be finely moved along the ion optical axis.   20. The ion implantation apparatus according to claim 17, wherein the mass separator is a fan-shaped magnet in particular.   20. The ion implantation apparatus according to claim 17, wherein the mass separator is, in particular, a Wien filter in which a magnetic pole and an electrode are orthogonal to each other.   20. The ion implantation apparatus according to claim 17, wherein a ratio of acceleration energy of ions irradiated to the sample with respect to initial energy with respect to emitted ions is 1.0 to 3.0. Ion implanter.   20. The ion implantation apparatus according to claim 17, further comprising a vacuum shut-off valve immediately below a crossover position of an Einzeln lens that focuses the shaped ion beam that has passed through the stencil mask. An ion implantation apparatus.   20. The ion implantation apparatus according to claim 17, further comprising an ion beam blocking shutter disposed immediately below a crossover position of an Einzeln lens that focuses the shaped ion beam that has passed through the stencil mask. An ion implantation apparatus characterized by that.   21. The ion implantation apparatus according to claim 19, further comprising: a shutter for blocking an ion beam immediately below a crossover point of an Einzeln lens that separates ions emitted from the ion source and focuses the ions after mass separation. An ion implantation apparatus characterized by being installed.   18. The ion implantation apparatus according to claim 17, wherein the stencil mask has a plurality of patterns for receiving ion irradiation on the stencil mask, has an exchange mechanism in a vacuum vessel, and selects an irradiation pattern from outside the vacuum. An ion implantation apparatus comprising the stencil mask control apparatus.   20. The ion implantation apparatus according to claim 17, wherein, in particular, the stencil mask has a plurality of patterns subjected to ion irradiation on the stencil mask, has an exchange mechanism in a vacuum vessel, and has an ion An ion implantation apparatus comprising a control device for selecting a pattern on a source and a stencil mask and adjusting at least one of irradiation ion current and energy.   18. The ion implantation apparatus according to claim 17, wherein the ion source is a plurality of ion sources that emit different kinds of dopant ions.   33. The ion implantation apparatus according to claim 32, wherein the stencil mask further includes a plurality of patterns subjected to ion irradiation on the stencil mask, has an exchange mechanism in a vacuum vessel, and is provided on the ion source and the stencil mask. An ion implantation apparatus comprising a control device for selecting a pattern and adjusting the strength of a mass separator. 37. The ion implantation apparatus according to claim 17, in particular, the sample is silicon, and the shaped ion beam that reaches the sample is any one of boron, phosphorus, and arsenic, and is applied to the sample. An ion implantation apparatus characterized in that a beam having an ultimate ion current of 0.1 μA or more and a region irradiated at a time of 1 cm ² or more is formed.   A multi-chamber process comprising a plurality of chambers for performing steps in a semiconductor manufacturing process, a wafer handler for loading and unloading wafers between them, and a wafer handler housing connected to the plurality of chambers and containing the wafer handler 25. A multi-chamber process apparatus, wherein at least one of the chambers is an ion implantation apparatus according to any one of claims 17 to 24.   The ion implantation method according to any one of claims 1 to 16, the ion implantation apparatus according to any one of claims 17 to 37, and the multi-chamber process apparatus according to claim 38. Semiconductor device and system using the same.

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