Method for implanting negative hydrogen ion and implanting apparatus

• US 6,335,535 B1
• Filed: 06/25/1999
• Issued: 01/01/2002
• Est. Priority Date: 06/26/1998
• Status: Expired due to Fees

• Current Assignee: Nissin Electric Company Limited
• Original Assignee: Nissin Electric Company Limited
• Inventors: Hayashi, Tsukasa, Miyake, Koji, Kuwahara, Hajime
• Primary Examiner(s): Anderson, Bruce
• Assistant Examiner(s): Wells, Nikita
• Application Number:
  US09/344,341
• Time in Patent Office: 921 Days
• Field of Search: 250/492.21, 250/492.2, 250/492.3, 250/423.R, 250/424, 313/359.1, 313/363.1, 315/111.21, 315/111.61
• US Class Current: 250/492.21
• CPC Class Codes: H01J 2237/006 Details of gas supplies, e.g. in an ion source, to a beam line, to a specimen or to a workpiece, H01J37/3244 takes precedence; environmental cells for electron microscopes H01J2237/2003; microscopes with environmental specimen chamber H01J2237/2608
• CPC Class Codes: H01J 2237/043 Beam blanking
• CPC Class Codes: H01J 2237/061 Construction
• CPC Class Codes: H01J 2237/08 Ion sources
• CPC Class Codes: H01J 37/32412 Plasma immersion ion implantation
• CPC Class Codes: H01L 21/0445 the devices having semiconductor bodies comprising crystalline silicon carbide multistep processes for the manufacture of said devices H01L29/66053
• CPC Class Codes: H01L 21/26506 in group IV semiconductors
• CPC Class Codes: H01L 21/76251 using bonding techniques
• CPC Class Codes: H01L 21/76254 with separation/delamination along an ion implanted layer, e.g. Smart-cut, Unibond
• CPC Class Codes: H01L 31/1804 comprising only elements of Group IV of the Periodic Table
• CPC Class Codes: Y02E 10/547 Monocrystalline silicon PV cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A method for implanting negative hydrogen ions includes the following steps. Plasma containing hydrogen is generated. Negative hydrogen ions are generated in the plasma. An electric field is formed between the plasma and a substrate. Negative hydrogen ions from the plasma is accelerated by using the electric field so as to implant negative hydrogen ions into a predetermined depth of a substrate.

Claims

1. A method for implanting negative hydrogen ions comprising the steps of:

generating plasma containing hydrogen;

generating negative hydrogen ions in the plasma;

forming an electric field between the plasma and a substrate using a multi-aperture electrode; and

accelerating negative hydrogen ions from the plasma by using the electric field so as to implant negative hydrogen ions into a predetermined depth of a substrate.

2. The method for implanting negative hydrogen ions according to claim 1, wherein one or a plurality of the substrates are disposed, mass separation from the plasma is not performed and negative hydrogen ions are implanted to the overall surface of the one or the plural substrates.

3. The method for implanting negative hydrogen ions according to claim 1, wherein the substrate is heated during or after implantation of the negative hydrogen ions to form voids at the predetermined depth.

4. The method for implanting negative hydrogen ions according to claim 1, wherein the negative hydrogen ions are accelerated by a method of disposing a plurality of drawing electrodes between the plasma and the substrate, and voltage is applied to the plural drawing electrode so as to form an electric field among the drawing electrodes so that the negative hydrogen ions are extracted by the electric field.

5. The method for implanting negative hydrogen ions according to claim 4, wherein the plasma generating is periodically turned on/off.

6. The apparatus for implanting pulse bias negative hydrogen ions according to claim 5, further comprising a mechanism for turning said plasma generating means on/off, and a timing adjusting circuit for determining timing at which generation of the plasma is permitted/inhibited and application of the positive bias to said suscepter is permitted/inhibited;

wherein positive bias voltage is applied to said suscepter immediately after said plasma generating means has been turned off.

7. The apparatus for implanting pulse bias negative hydrogen ions according to claim 5, further comprising a magnetic-field forming means for forming a magnetic field in said plasma chambers which is disposed in said plasma chamber or on the outside of said plasma chamber to divide said plasma chamber into two sections so that penetration of electrons having high energy is prevented by the magnetic field;

wherein either of said plasma chambers generates plasma, and said suscepter and the substrate are disposed in the other plasma chamber.

8. The method for implanting negative hydrogen ions according to claim 1, wherein the substrate is exposed to the plasma, the plasma generating is periodically turned on/off, positive pulse voltage is applied to the substrate in a period approximately 10 μ

sec after a moment at which said plasma generating is turned off to a moment at which said plasma generating is turned on so that negative ions beam in the plasma which is in a quenching state is accelerated so as to be implanted into the substrate.

9. The method for implanting pulse bias negative hydrogen ions according to claim 1, wherein Cs is supplied to a plasma chamber incorporating means for generating plasma by applying high frequency to a high-frequency coil, Cs is disposed on the surface of a conductive target disposed in said plasma chamber, negative voltage is applied to said target to sputter said target with positive ions so that hydrogen plasma containing negative hydrogen ions at a high concentration is generated.

10. The method for implanting pulse bias negative hydrogen ions according to claim 1, wherein said plasma generating means is periodically turned on/off, and the substrate is applied with positive pulse voltage in a period from turning of said plasma generating means off to again turning of said plasma generating means on after a lapse of 10 μ

sec.

11. The negative hydrogen ion beam implanting method according to claim 1, wherein Cs is supplied to the plasma chamber incorporating means for generating plasma by supplying high frequency to a high-frequency coil, Cs is deposited on the surface of a conductive target disposed in said plasma chamber and negative voltage is applied to the target so that the target is sputtered with positive ions so as to generate hydrogen plasma containing a high concentration of negative hydrogen ions.

12. The negative hydrogen ion beam implanting method according to claim 1, wherein said plasma generating means is periodically turned on/off, and DC voltage is applied to said extracting electrode system in a period from a moment at which said plasma generating means has been turned off to a moment after a lapse of 10 μ

sec at which said plasma generating means has again be turned on so as to extract the negative hydrogen ion beam.

13. The negative hydrogen ion beam implanting apparatus according to claim 5, further comprising:

a switch for turning on/off said plasma generating means;

a switch for turning on/off generation of plasma and DC voltage which is supplied to said extracting electrode system; and

a delay circuit for determining the relationship between timing at which said plasma generating means is turned on/off and timing at which the voltage of said extracting electrode system is turned on/off;

wherein DC voltage is supplied to said extracting electrode system immediately after said plasma generating means has been turned off so as to extract a negative ion beam.

14. An apparatus for implanting negative hydrogen ions comprising:

hydrogen generating means for generating plasma containing hydrogen;

negative hydrogen ions generating means for generating negative hydrogen ions in the plasma; and

multi-aperture electrode for forming an electric field between the plasma and a substrate;

wherein negative hydrogen ions from the plasma is accelerated by using the electric field so as to implant negative hydrogen ions into a predetermined depth of a substrate.

15. The apparatus for implanting negative hydrogen ions according to claim 14, wherein one or a plurality of the substrates are disposed, mass separation from the plasma is not performed, and negative hydrogen ions are implanted to the overall surface of the one or the plural substrates.

16. The apparatus for implanting negative hydrogen ions according to claim 14, further comprising heating means for heating the substrate during or after implantation of the negative hydrogen ions to form voids at the predetermined depth.

17. The apparatus for implanting negative hydrogen ions according to claim 14, further comprising a plurality of drawing electrodes between the plasma and the substrate, which accelerates the negative hydrogen ions;

wherein voltage is applied to the plural drawing electrode so as to form an electric field among the drawing electrodes so that the negative hydrogen ions are extracted by the electric field.

18. The apparatus for implanting negative hydrogen ions according to claim 17, wherein the plasma generating means is periodically turned on/off.

19. A method for implanting negative hydrogen ions according to claim 14, wherein the substrate is exposed to the plasma, the plasma generating means is periodically turned on/off, positive pulse voltage is applied to the substrate in a period approximately 10 μ

sec after a moment at which said plasma generating is turned off to a moment at which said plasma generating is turned on so that negative ions beam in the plasma which is in a quenching state is accelerated so as to be implanted into the substrate.

20. A method for implanting pulse bias negative hydrogen ions to a predetermined depth of a substrate comprising the steps of:

causing plasma generating means to generate plasma containing hydrogen;

exposing a substrate to the hydrogen plasma;

applying positive pulse voltage to the substrate; and

generating an electric field between the plasma and the substrate using a multi-aperture electrode so that negative hydrogen ions contained in the plasma are implanted to a predetermined depth of the substrate.

21. The method for implanting pulse bias negative hydrogen ions according to claim 20, wherein a magnetic field for capturing electrons is formed in an intermediate portion of a plasma chamber for generating plasma, the plasma generating means generates plasma in a first plasma chamber in either side of the magnetic field, the substrate is disposed in a second plasma chamber, the magnetic field inhibits movement of high energy electrons to said second plasma chamber, and collisions of electrons, neutron atoms and molecules are enhanced in said second plasma chamber so that the concentration of negative hydrogen ions is raised.

22. The apparatus for implanting pulse bias negative hydrogen ions comprising:

a plasma chamber which is a space for generating plasma capable of being brought to a vacuum state;

plasma generating means for generating plasma in said plasma chamber;

a gas introducing opening for introducing gas containing hydrogen atoms into said plasma chamber;

a gas exhausting unit for exhausting the gas from said plasma chamber;

a multi-aperture electrode for forming an electric field between the plasma and a substrate;

a suscepter which is disposed in said plasma chamber and on which the substrate is placed;

a positive bias power source for applying positive voltage bias to said suscepter;

a switch disposed between said positive bias power source and said suscepter; and

a mechanism for applying positive voltage bias to the substrate in a pulsing manner.

23. The apparatus for implanting pulse bias negative hydrogen ions according to claim 22, further comprising a conductive target disposed in said plasma chamber incorporating means for generating plasma by applying high frequency to a high-frequency coil, a negative bias power source for applying negative voltage to said target, an oven for generating steam of Cs, Rb or K, and a nozzle for introducing steam generating by the oven into said target.

24. A negative hydrogen ion beam implanting method for implanting hydrogen ions into a predetermined depth of a substrate, comprising the steps of:

generating plasma containing hydrogen in a plasma chamber by a plasma generating means;

extracting a negative hydrogen ion beam from the plasma by an extracting electrode system incorporating a plurality of multi-aperture electrode plates each having a pore distribution in a range wider than the diameter of the substrate; and

implanting the negative hydrogen ion beam into a predetermined depth of the substrate.

25. The negative hydrogen ion beam implanting method according to claim 24, wherein a magnetic field for capturing electrons is formed in an intermediate portion of the plasma chamber for generating the plasma, the plasma is generated by a plasma generating means in a first plasma chamber disposed on either side of the magnetic field, the extracting electrode system is provided for an opening portion of a second plasma chamber so that movement of high-energy electrons in the first plasma chamber is prevented by the magnetic field, collision of low-energy electrons, neutron atoms and molecules is enhanced in said second plasma chamber so as to raise the density of negative ions so that the negative hydrogen ion beam is extracted from said second plasma chamber so that the negative hydrogen ion beam is implanted into the substrate.

26. The negative hydrogen ion beam implanting apparatus comprising:

a plasma chamber which is a space for generating plasma, the pressure can be reduced to a vacuum;

plasma generating means for generating the plasma in said plasma chamber;

a gas introducing opening for introducing gas containing hydrogen atoms into said plasma chamber;

a gas exhaust unit for exhausting gas from said plasma chamber;

a plurality of extracting electrode systems disposed in an opening portion of said plasma chamber and each incorporating a porous plate having a diameter larger than the diameter of a substrate;

a power source for applying high negative voltage and positive voltage to an extracting electrode system to extract the negative ion beam from the plasma; and

a suscepter which is disposed downstream of said extracting electrode system and on which a semiconductor substrate, an insulating substrate or a metal substrate is mounted.

27. A negative hydrogen ion beam implanting apparatus according to claim 26, further comprising:

a magnetic-field forming means for forming a magnetic field in said plasma chamber, which is disposed in said plasma chamber or on the outside of said plasma chamber to divide said plasma chamber into two sections so that penetration of electrons having high energy is prevented by the magnetic field;

wherein either of said plasma chambers generates plasma, and said suscepter and the substrate are disposed in the other plasma chamber.

28. The apparatus for implanting pulse bias negative hydrogen ions according to claim 26, further comprising a conductive target disposed in said plasma chamber incorporating means for generating plasma by applying high frequency to a high-frequency coil, a negative bias power source for applying negative voltage to said target, an oven for generating steam of Cs, Rb or K, and a nozzle for introducing steam generating by the oven into said target.

29. A method for implanting negative hydrogen ions comprising the steps of:

generating plasma containing hydrogen;

generating negative hydrogen ions in the plasma;

forming an electric field between the plasma and a substrate; and

accelerating negative hydrogen ions from the plasma by using the electric field so as to implant negative hydrogen ions into a predetermined depth of a substrate;

wherein the substrate is exposed to the plasma, the plasma generating is periodically turned on/off, positive pulse voltage is applied to the substrate in a period approximately 10 μ

sec after a moment at which said plasma generating is turned off to a moment at which said plasma generating is turned on so that negative ions beam in the plasma which is in a quenching state is accelerated so as to be implanted into the substrate.

30. A method for implanting negative hydrogen ions comprising the steps of:

generating plasma containing hydrogen;

generating negative hydrogen ions in the plasma;

forming an electric field between the plasma and a substrate; and

accelerating negative hydrogen ions from the plasma by using the electric field so as to implant negative hydrogen ions into a predetermined depth of a substrate;

wherein the substrate is exposed to the plasma, the plasma generating means is periodically turned on/off, positive pulse voltage is applied to the substrate in a period approximately 10 μ

sec after a moment at which said plasma generating is turned off to a moment at which said plasma generating is turned on so that negative ions beam in the plasma which is in a quenching state is accelerated so as to be implanted into the substrate.

31. A method for implanting negative hydrogen ions comprising the steps of:

generating plasma containing hydrogen;

generating negative hydrogen ions in the plasma;

forming an electric field between the plasma and a substrate; and

accelerating negative hydrogen ions from the plasma by using the electric field so as to implant negative hydrogen ions into a predetermined depth of a substrate;

wherein said plasma generating means is periodically turned on/off, and the substrate is applied with positive pulse voltage in a period from turning of said plasma generating means off to again turning of said plasma generating means on after a lapse of 10 μ

sec.