JP3257192B2 - Semiconductor processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor processing method for recovering solid crystallinity and activating impurities at a low temperature by using an ion beam.

[0002]

2. Description of the Related Art Conventionally, heat treatment has been exclusively used for recovering crystallinity and activating impurities after ion implantation. Recently, it has been observed that disordered crystallinity is restored when an ion beam is irradiated parallel to the crystal axis of the semiconductor, that is, under the so-called channeling condition. Separate volumes P.524, 10a-S
ZB-1). By utilizing this phenomenon, the crystallinity can be recovered at a low temperature.

[0003]

However, in the conventional method, an ion beam is irradiated on one crystal axis under a condition of a single energy. Since the ion beam is irradiated only on one crystal axis in this way, interstitial atoms shifted from the crystal axis in the semiconductor which undergo displacement due to interaction with ions as shown in FIG. 12 cause channeling. Will receive a displacement in a random direction with respect to the crystal axis,
There is a problem that the position is simply shifted from the position before the ion irradiation. Also, as shown in FIG. 12, when an ion beam having a single energy is irradiated, the distance that can be approached to the crystal axis is naturally determined. There was also the problem of being done. For these reasons, conventional methods have not been able to completely restore crystallinity.

[0004] The present invention has been made in view of the above problems,
Limiting the direction of displacement by making the particle beam incident on multiple channeling axes and changing the incident energy to gradually reduce the gap between interstitial atoms (target solid substrate atoms and impurity atoms) It is an object of the present invention to provide a method for finer recovery of crystallinity and activation of impurities.

[0005]

According to a first aspect of the present invention, there is provided a method for processing a semiconductor, comprising the steps of: improving the crystallinity of a semiconductor having a disordered crystallinity; At an angle, by irradiating the activation ion beam several times with gradually changing energy, the particles of the activation ion beam in the semiconductor are applied to atoms constituting the semiconductor,
The method is characterized in that the atoms are gradually moved on a crystal axis to improve crystallinity.

In order to achieve the above object, a semiconductor processing method according to a second aspect of the present invention is to implant an impurity into a semiconductor by ion implantation or the like using an ion beam for impurity implantation, and to remove impurities in the semiconductor. In the method of performing the activation, by irradiating the activation ion beam several times with gradually changing energy at an angle at which channeling occurs in the semiconductor, the particles of the activation ion beam in the semiconductor are irradiated. The method is characterized in that the impurity is activated by gradually moving the impurity into a lattice in contact with the impurity.

A semiconductor processing method according to a third aspect of the present invention configured to achieve the above object is a method for improving the crystallinity of a semiconductor having disordered crystallinity, wherein the semiconductor is activated at a plurality of angles at which channeling occurs in the semiconductor. By irradiating the activation ion beam, the particles of the activation ion beam are applied to atoms constituting the semiconductor in the semiconductor, and the atoms are moved on a crystal axis to improve crystallinity. Features.

In a fourth aspect of the present invention, there is provided a method for processing a semiconductor, comprising the steps of: implanting an impurity into a semiconductor by ion implantation using an ion beam for impurity implantation; In the method of performing the activation, the semiconductor is irradiated with an activation ion beam at a plurality of angles at which channeling occurs, whereby particles of the activation ion beam are applied to the impurities in the semiconductor, and the impurities are latticed. And activates the impurities by moving the impurities into the substrate.

[0009]

According to the first aspect of the present invention, a semiconductor having disordered crystallinity is irradiated with an activation ion beam at an angle at which the semiconductor causes channeling, and particles of the ion beam constitute a semiconductor. Hit the atom. After that, irradiation is performed at the same angle while changing the energy. By performing this several times, atoms are gradually moved on the crystal axis,
Improve crystallinity.

According to the second aspect of the present invention, an impurity is implanted, and an impurity is irregularly introduced into the semiconductor and the lattice is distorted. Irradiates the particles of the ion beam with the impurities that have entered the irregularities. After that, irradiation is performed at the same angle while changing the energy. By performing this several times, the impurities are gradually moved, corrected to a regular arrangement, and activated.

According to the fourth aspect of the present invention, the semiconductor having disordered crystallinity is irradiated with an activating ion beam at a plurality of angles at which the semiconductor causes channeling, and particles of the ion beam constitute a semiconductor. Hit the atom that is. Thereby, the crystallinity can be improved from multiple directions. According to the fifth aspect of the present invention, an impurity is implanted, and an activation ion beam at a plurality of angles at which the semiconductor causes channeling is applied to a semiconductor whose lattice is distorted because the impurity enters irregularly. Irradiate and expose the particles of this ion beam to impurities that have entered irregularly. As a result, impurities are moved from multiple directions, corrected into a regular arrangement, and activated.

[0012]

According to the first aspect of the present invention, the atoms are gradually moved on the crystal axis to improve the crystallinity. As a result, fine movement can be realized, and crystallinity can be greatly improved. According to the second aspect of the present invention, activation is performed by gradually moving impurities into the lattice. As a result, fine movement can be realized, and crystallinity can be greatly improved.

According to the fourth aspect of the present invention, since atoms are moved at a plurality of angles, fine movement can be realized, and crystallinity can be greatly improved. According to the fifth aspect of the present invention, since impurities are moved at a plurality of angles, fine movement can be realized, and crystallinity can be greatly improved.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) An example of an apparatus for embodying the present invention and an embodiment thereof will be described below with reference to the drawings. FIG. 1 shows an example of an apparatus for irradiating X-rays for adjusting a set angle of a target semiconductor substrate, and FIG. 2 is an enlarged view of the inside of a target semiconductor substrate holding vacuum chamber 13. First, the target semiconductor substrate 131 is fixed to the goniometer 132 in the target semiconductor substrate holding vacuum chamber 13. Here, the target semiconductor substrate 131 is a semiconductor having disordered crystallinity. The goniometer 132 needs to finely adjust the rotation angle and the inclination angle with respect to the X-rays 12 incident on the target semiconductor substrate 131, and it is preferable that the goniometer 132 can be controlled by a computer if possible.

Next, a method of setting the channeling angle of the target semiconductor substrate 131 by irradiating the target semiconductor substrate 131 fixed as described above with X-rays will be described. First, X-rays 12 are emitted from the X-ray source 15 and reflected by the X-ray reflector 14 fixed to the driving device 18 so that the target semiconductor substrate 131
Is irradiated with X-rays 12. After the conditions for irradiating X-rays are thus prepared, the angle of the target semiconductor substrate 131 is actually adjusted. The method will be described below. For example, Si
It is assumed that a (100) substrate is used. In this case, <
Since the <100> axis is perpendicular to the substrate, the angle is first set so that the X-ray is almost perpendicularly incident.
Then, the diffraction pattern is formed on the X-ray detector 133 by finely adjusting the angle. The X-ray detector 133 is composed of a plurality of minute detectors and has an X-ray intensity of 3
It can measure the dimensional distribution. Once the set angle of the <100> axis is determined, other crystal axes, for example, <110>
Since the relative angular relationship of the axis and the <111> axis is known, the angle of the substrate is set to an angle near the axis, and the above-described <100>
Fine adjustment may be performed in the same manner as in the method of determining the angle of the target semiconductor substrate 131 with respect to the axis. Thus, the angle at which the particle beam is incident is determined.

It is preferable that the crystal axis on which the particle beam is incident has as low an index as possible. <100> above
In addition to the axis and the <111> axis, for example, the <110> axis may be used. This is because the particle beam is particularly likely to cause channeling with respect to a low-index crystal axis. By irradiating the particle beam in the channeling state, the particle beam easily travels along the crystal axis. Therefore, it is possible to prevent the particles and the semiconductor constituent atoms from elastically or inelasticly colliding with each other, giving energy to the atoms, and changing the crystallinity and disturbing the atoms.

After setting the angle of the target semiconductor substrate 131 by the above method, the target semiconductor substrate 131 is irradiated with the activating particle beam 11 at this angle. At this time, the activation particle beam is first irradiated with low energy (for example, E1), and the energy intensity is gradually increased (E1 → E2 →
E3, where E1 <E2 <E3) Irradiate several times. The particle beam for recrystallization used at this time is Ar ⁺ , Ne ⁺ ,
Si ⁺ , H ⁺ , He ⁺ , electrons, positrons and the like can be mentioned as candidates.

Next, the action occurring in the target semiconductor substrate 131 at this time will be described. FIG. 3 shows the target semiconductor 131.
1 schematically shows the atomic arrangement and the incident state of a particle beam. Thus, the atoms in the semiconductor are arranged with a periodic structure (locally). In this case, as the above-mentioned low index channeling axes for the particle beam 22, crystal axes 23, 24, and 25 as shown in the figure can be cited as candidates. In this embodiment, the particle beam is irradiated along the crystal axis 24. Consider the case. FIGS. 4 (a) to 4 (a) to 4 (c) show the effect of the channeled particle beam on the interstitial atoms 21 shifted from the crystal axis 24. FIG.
(C).

FIG. 4A shows a phenomenon when the particle beam 22 having a relatively low energy is incident on the channeling shaft 23 in FIG. In this case, the incident particle beam 22 having the energy E1 is
Can only approach up to the distance D1. Therefore, energy is hardly applied to the interstitial atoms 25 located within a distance of D1 from the crystal axis due to collision with the particle beam, and the degree of the shift is hardly corrected. On the other hand, since the energy due to the collision with the particle beam is applied to the interstitial atoms 31 located at a distance of D1 or more from the crystal axis, the deviation is slightly corrected.

Next, FIG. 4B shows a phenomenon when the energy of the particle beam is E2 which is larger than E1 in FIG. 4A. The particle beam 22 having the energy E2 can approach from the crystal axis 24 to a distance D2. Here, D2 is smaller than the distance D1 in FIG.
Therefore, in this case, the range in which the deviation can be corrected as compared with the energy E1 becomes large, and the interstitial atoms are further increased in the crystal axis
And the crystallinity is improved.

FIG. 4C shows a phenomenon when the energy of the particle beam is further increased. In this case, the energy is E3 and can be approached from the crystal axis 24 to a distance D3. Here, D3 is smaller than the distance D2 in FIG. Therefore, in this case, the range in which the deviation can be corrected as compared with the energy E2 becomes large, and the state where the interstitial atoms are further pushed into the crystal axis 24 becomes closer, and the crystallinity is improved. As described above, the interstitial atoms can be sequentially moved toward the crystal axis by gradually increasing the energy of the incident particle beam.

As described above in detail, in the present embodiment, recrystallization and activation can be realized at a relatively low temperature because a particle beam is used. By using this method, selective crystal growth and impurity redistribution can be substantially prevented. Without this, fine-grained recrystallization can be realized, and a high-performance microelectronic device can be formed. In this embodiment, in order to promote recrystallization, impurity atom addition treatment (for example, ion implantation) may be performed on the target semiconductor substrate 131 having disordered crystallinity in advance.

(Second Embodiment) A second embodiment of the present invention will be described below with reference to the drawings. In the present embodiment, the first
The target semiconductor substrate 131 is irradiated with the activating particle beam 11 at a plurality of angles with respect to the angles of the plurality of channeling conditions determined in the embodiment while changing the intensity of the energy as in the first embodiment. By performing the recovery of crystallinity using channeling on a plurality of channeling axes in this manner, further recovery of crystallinity is expected. FIGS. 5A and 5B show this phenomenon.

FIG. 5A shows a case where the correction of interstitial atoms is performed on the channeling axis 25 in FIG. 3 after the correction of interstitial atoms on the channeling axis 24 in FIG. In this case, the interstitial atoms change the energy of the activating particle beam 22 with respect to the axis 25 where channeling occurs, as in the case of the above-described correction for the channeling axis 24, and gradually correct the position of the semiconductor constituent atoms. do.

FIG. 5B shows the case where the interstitial atoms are further corrected for the channeling axis 23 of FIG. In this case, the interstitial atoms are subjected to position correction with respect to the axis 23 where channeling is occurring, as in the case of the above-described correction for the channeling axes 24 and 25, and gradually approach the crystal axis. As described above, the interstitial atoms are pushed into a plurality of crystal axes by the activating particle beam, so that finer crystallinity can be improved more finely than the conventional channeling for one axis.

In this embodiment, the energy of the particle beam applied to a plurality of channeling axes is changed. However, the irradiation may be performed with the energy fixed as in the prior art. As described in detail above, in the present embodiment, recrystallization and activation can be realized at a relatively low temperature, and by using this method, a fine-grained recrystallization can be performed with almost no selective crystal growth and impurity redistribution. Accordingly, it is possible to form a high-performance microelectronic device.

(Third Embodiment) A third embodiment of the present invention will be described below with reference to the drawings. In the first and second embodiments, the angle at which the target semiconductor substrate 131 causes channeling by X-rays was found, and then the activation particle beam was irradiated along this angle. In the present embodiment, an angle condition setting particle beam 31 is used instead of X-rays, and the channeling angle of the target semiconductor substrate 331 is found by utilizing the channeling phenomenon caused by the angle setting particle beam 31. FIG. 6 shows an embodiment of an apparatus embodying this method. The target semiconductor substrate 331 can be irradiated with the angle setting particle beam 31 and the activation particle beam 32 using the same accelerator. Thereby, the angle setting particle beam 31 and the activation particle beam 32 can be passed on the same orbit. Here, in order to minimize damage to the target semiconductor substrate 331 by the angle setting particle beam 31, the angle setting particle beam 31 narrows the beam diameter, and forms a single crystal region on the target semiconductor substrate 331 which is not to be formed with an element. It is desirable to irradiate only. Also,
Various semiconductor detectors, channeltrons, and the like may be used for measuring the backscattered particle beam.

In this apparatus, the same ions as the ions of the activation particle beam 32 are used as the ions of the angle setting particle beam 31. When the target semiconductor substrate 331 is irradiated with the angle setting particle beam 31 and a channeling phenomenon occurs in the target semiconductor substrate 331, the ratio of the backscattered particles emitted from the target semiconductor substrate 331 into a vacuum to the incident particles decreases. FIG. 7 shows this state.
The rate of reduction of the rear particles becomes particularly remarkable for a low-index crystal axis. The backscattered particle beam 311 reflected and emitted from the target semiconductor substrate constituent atoms 334 is detected by the backscattered particle detector 34, and the reduction ratio is determined by the angle setting particle beam 3.
By sequentially measuring the incident angle of one, the minimum value of the decrease rate is determined as the angle condition of each crystal axis.

Thereafter, the target semiconductor substrate 331 is irradiated with the activating particle beam 32 by using the same method as in the first and second embodiments, and the target semiconductor substrate 331 is recrystallized. In this embodiment, since an X-ray source for generating X-rays, a reflector thereof, and the like are not required, simplification of the apparatus, cost reduction, reduction in man-hours in a production process, and the like can be expected. In this embodiment,
The same ion is used as the ion of the angle setting particle beam 31 and the same ion of the activation particle beam 32, and the same accelerating device is used. However, these ions are not necessarily required to be the same and are different. Ions may be used. In this case, the same accelerating device may be used,
Also, separate devices may be used.

FIG. 8 shows an example of an apparatus for accelerating an angle setting particle beam 41 and an activation particle beam 42 by different accelerators. The trajectory of the angle setting particle beam 41 extracted from the angle setting particle beam generation accelerator 45 is bent by the magnetic field generator 49 and irradiated to the target semiconductor substrate 431, and the emitted backscattered particles are detected as backscattered particles. Vessel 4
33 to detect. Also in this case, the angle setting particle beam 41 is used.
In order to suppress damage to the target semiconductor substrate 431 as much as possible, it is desirable that the angle setting particle beam 41 be used to narrow the beam diameter and irradiate only a single crystal region on the target semiconductor substrate 431 where an element is not to be formed. .

FIG. 9 shows an example of an apparatus for accelerating an angle setting particle beam 51 and an activating particle beam 52 by separate accelerators. In this example, an electron beam is used as the angle setting particle beam 51. Electron beam 51 extracted from electron beam source 55
The orbit is bent by the magnetic field generator 59 and irradiated onto the target semiconductor substrate 531, and the three-dimensional distribution of the diffraction pattern formed by the target semiconductor substrate 531 is measured by the electron beam detector 533. The diffraction pattern is unique to each crystal plane, and the angle condition at which the diffraction spots are generated may be set as the irradiation condition of the activation particle beam. As a means for bending the electron beam, an electric field generator 59 may be used as shown in FIG.

(Fourth Embodiment) Hereinafter, a fourth embodiment of the present invention will be described with reference to the drawings. In the first to third embodiments, the activation particle beam is applied to the target semiconductor substrate having disordered crystallinity, and the crystal structure in the target semiconductor substrate is improved. However, in the present invention, by using a semiconductor substrate into which an impurity has been implanted as a target semiconductor substrate, the impurity in the semiconductor substrate can be activated.

FIG. 11 is a diagram showing a state in a semiconductor substrate to which impurities are added by ion implantation or the like. The lattice composed of the constituent atoms 66 of the target semiconductor substrate is partially distorted because the implanted impurities 61 enter the lattice irregularly. By irradiating the impurity particles 61 in such a semiconductor substrate with the activating particle beam 62 by the above-described method, the impurities that have entered the irregularities can be arranged in a regular array. As a result, lattice distortion is reduced, and impurities can be activated. At this time, similarly to the first and second embodiments, fine activation can be realized by changing the energy of the activating particle beam 62 or irradiating a plurality of axes.

In the present invention, X for setting the other angle is used.
If the beam, electron beam, or particle beam deviates from the same trajectory as the activation particle beam, the angle deviation between the activation particle beam and the angle setting beam must be grasped in advance, and After setting the angle by the angle setting beam according to the same principle as described above, it is preferable to correct the incident angle of the target solid substrate with respect to the activation particle beam by the deviation and then irradiate the activation particle beam. In this embodiment, the energy of the particle beam is changed to keep the energy constant during the irradiation. However, the energy may be changed continuously (E1 → E3) during one irradiation.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of an apparatus embodying the present invention.

FIG. 2 is an enlarged view of a vacuum chamber for holding a target semiconductor substrate of the apparatus shown in FIG.

FIG. 3 is a diagram showing an atomic arrangement in a semiconductor substrate and an incident state of a particle beam in the first embodiment of the present invention.

FIG. 4 is a diagram showing a state inside a semiconductor substrate according to the first embodiment of the present invention.

FIG. 5A is a diagram illustrating a state inside a semiconductor substrate according to a second embodiment of the present invention. (B) It is a figure showing the situation in the semiconductor substrate in a 2nd example of the present invention.

FIG. 6 is a diagram showing an embodiment of an apparatus embodying the present invention.

FIG. 7A is a diagram showing a state inside a semiconductor substrate according to a third embodiment of the present invention. (B) It is the figure showing the intensity distribution of the backscattering particle in (a).

FIG. 8 is a diagram showing one embodiment of an apparatus embodying the present invention.

FIG. 9 is a diagram showing an embodiment of an apparatus embodying the present invention.

FIG. 10 is a diagram showing one embodiment of an apparatus embodying the present invention.

FIG. 11 is a diagram illustrating a state inside a semiconductor substrate according to a fourth embodiment of the present invention.

FIG. 12 is a diagram showing a state inside a semiconductor substrate in conventional recrystallization.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 X-ray 12 Activation particle beam 13 Target semiconductor substrate holding vacuum chamber 131 Target semiconductor substrate 132 Goniometer 133 X-ray detector 134 Diffraction spot 14 X-ray reflector 15 X-ray source 16 Activation particle beam generator accelerator 17 Beam line 18 Drive unit 21, 26 Interstitial atom 22 Activation particle beam 23, 24, 25 Low index channeling axis 31 Activation particle beam 311 Backscattered particle beam 32 Angle condition setting particle beam 33 Target semiconductor substrate holding Vacuum chamber 331 Target semiconductor substrate 332 Goniometer 333 Angular condition setting particle beam detector 334 Target semiconductor substrate constituent atoms 34 Backscattering particle detector 36 Activation particle beam generating accelerator 37 Beam line 41 Angle condition setting particle beam 42 Active Particle beam 43 target Vacuum chamber 431 for holding conductive substrate 431 Target semiconductor substrate 432 Goniometer 433 Backscattered particle detector 45 Accelerator for generating particle beam for setting angle condition 46 Accelerator for generating particle beam for activation 47 Beamline 49 Magnetic field generator 51 Electron beam 52 Activation Particle beam for target 53 Vacuum tank for holding target semiconductor substrate 531 Target semiconductor substrate 532 Goniometer 533 Electron beam detector 55 Electron beam source 56 Accelerator for generating particle beam for activation 57 Beam line 58 Drive device 59 Electric field generator 61 Impurity atom 62 Activity Particle beam 63 Low index channeling axis 64 Low index channeling axis 65 Low index channeling axis 66 Target semiconductor substrate constituent atoms

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-7-114799 (JP, A) JP-A-5-198522 (JP, A) JP-A-3-8323 (JP, A) JP-A-3-3 35521 (JP, A) JP-A-63-142631 (JP, A) JP-A-7-94436 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/265

Claims (5)

(57) [Claims] 1. A method for improving the crystallinity of a semiconductor having a disordered crystallinity, comprising irradiating an activation ion beam several times with gradually changing energy at an angle at which channeling occurs in the semiconductor. And a method of treating a semiconductor in which particles of the activation ion beam are applied to atoms constituting the semiconductor in the semiconductor, and the atoms are gradually moved on a crystal axis to improve crystallinity. 2. A method for injecting impurities into a semiconductor by an ion implantation method using an ion beam for impurity implantation and activating the impurities in the semiconductor, wherein the activation ions are formed at an angle at which channeling occurs in the semiconductor. By irradiating the beam several times with gradually changing energy, the particles of the activation ion beam are applied to the impurities in the semiconductor, and the impurities are gradually moved into a lattice to remove the impurities. A method for treating a semiconductor to be activated. 3. The semiconductor processing method according to claim 1, wherein the activation ion beam is irradiated from a plurality of angles at which channeling occurs in the semiconductor. 4. A method for improving the crystallinity of a semiconductor having disordered crystallinity, wherein the semiconductor is irradiated with an activation ion beam at a plurality of angles at which channeling occurs.
A semiconductor treatment method in which particles of the ion beam for activation are applied to atoms constituting the semiconductor in the semiconductor, and the atoms are moved on a crystal axis to improve crystallinity. 5. A method for injecting impurities into a semiconductor by an ion implantation method using an ion beam for impurity implantation and activating the impurities in the semiconductor, wherein the semiconductor is activated at a plurality of angles at which channeling occurs. A method of treating a semiconductor, comprising irradiating particles of the activation ion beam in the semiconductor with the impurities by irradiating the semiconductor with the ions for the activation, and moving the impurities into a lattice to activate the impurities.