Ion implantation apparatus, ion generating apparatus and semiconductor manufacturing method with ion implantation processes

• US 6,335,534 B1
• Filed: 04/15/1999
• Issued: 01/01/2002
• Est. Priority Date: 04/17/1998
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Murakoshi, Atsushi, Okumura, Katsuya, Suguro, Kyoichi
• Primary Examiner(s): Anderson, Bruce
• Assistant Examiner(s): Wells, Nikita
• Application Number:
  US09/291,967
• Time in Patent Office: 992 Days
• Field of Search: 250/492.21, 250/492.2, 250/423.R, 250/424, 250/425
• US Class Current: 250/492.21
• CPC Class Codes: H01J 2237/31711 using mask
• CPC Class Codes: H01J 37/3171 for ion implantation plasma immersion ion implantation H01J37/32412
• CPC Class Codes: H01L 21/26586 characterised by the angle between the ion beam and the crystal planes or the main crystal surface
• CPC Class Codes: H01L 21/266 using masks H01L21/26586 takes precedence
• CPC Class Codes: H01L 21/823842 gate conductors with different gate conductor materials or different gate conductor implants, e.g. dual gate structures
• CPC Class Codes: H01L 27/092 complementary MIS field-effect transistors
• CPC Class Codes: H01L 29/66545 using a dummy, i.e. replacement gate in a process wherein at least a part of the final gate is self aligned to the dummy gate

Abstract

An electrically conductive mask having openings formed is located above a semiconductor substrate and ions are implanted into the surface of the semiconductor substrate through the electrically conductive mask, thereby forming ion implanted layers. For ion implantation under different conditions, a dedicated electrically conductive mask is used wit each ion implantation step.

Claims

1. An ion implantation apparatus comprising:

an electrically conductive mask having an opening and located apart from an object to be processed, said opening including a tapered structure in which a diameter of the opening increases in a direction away from the object to be processed; and

an ion implanting section which implants ions into the object through the opening of the electrically conductive mask.

2. An ion implantation apparatus according to claim 1, wherein a distance between the electrically conductive mask and the object is set to 15 μ

m or less.

3. An ion implantation apparatus according to claim 1, wherein the electrically conductive mask has another opening, and the apparatus further comprises a detecting section which detects ions that pass through the another opening of the electrically conductive mask.

4. An ion implantation apparatus according to claim 1, wherein the electrically conductive mask has a plurality of openings, and the apparatus further comprises a shutter for selectively covering a part of the openings from the ions.

5. An ion implantation apparatus according to claim 1, wherein the object to be processed is one of a semiconductor substrate and a semiconductor layer formed above the semiconductor substrate.

6. An ion implantation apparatus according to claim 1, wherein the electrically conductive mask is made of one of the same element as the object to be processed and a material that consists mainly of that element.

7. An ion implantation apparatus according to claim 1, wherein the electrically conductive mask has a plurality of mask areas with different opening patterns.

8. An ion implantation apparatus according to claim 7, wherein the opening pattern of each of the mask areas is selected such that a desired pattern is obtained when the opening patterns of the mask areas are superimposed upon each other.

9. An ion implantation apparatus according to claim 1, further comprising a first electrostatic chuck for holding the object to be processed and a second electrostatic chuck for holding the electrically conductive mask.

10. An ion generation apparatus comprising:

a container formed in a shape of a box;

a holding section which holds a solid material that includes a plurality of elements on an inner wall of the container;

a plasma generating section which generates a plasma in the container to thereby sputtering the solid material held by the holding section in the container for generating ions of the plurality of elements;

a gas introducing section which introduces into the container a plasma-generating gas for generating a plasma used for sputtering the solid material;

a liquid trapping section which traps a liquid resulting from the sputtering; and

a taking out section which takes plural species of ions generated by sputtering the solid material out of the container.

11. An ion generation apparatus according to claim 10, wherein the holding section acts as the liquid trapping section.

12. An ion implantation apparatus comprising:

a container formed in a shape of a box;

a holding section which holds a solid material that includes a plurality of elements on the inner wall of the container;

a plasma generating section which generates a plasma in the container to thereby sputtering the solid material held by the holding section for generating ions of the plurality of elements;

a gas introducing section which introduces into the container a gas for generating a plasma used for sputtering the solid material;

a liquid trapping section which traps a liquid resulting from the sputtering;

a taking out section which takes a plural species of ions generated by sputtering the solid material out of the container; and

a directing section which directs a selected desired species ion of the plural species of ions taken out of the container by the taking out section onto an object to be processed.

13. An ion implantation apparatus comprising:

a container formed in a shape of a box;

a holding section which holds a solid material that includes a plurality of elements on a inner wall of the container;

a plasma generating section which generates a plasma in the container to thereby sputtering the solid material held by the holding section for generating ions of the plurality of elements;

a gas introducing section which introduces into the container a gas for generating a plasma used for sputtering the solid material;

a liquid trapping section which traps a liquid resulting from the sputtering;

a taking out section which takes a plural species of ions generated by sputtering the solid material out of the container;

a directing section which directs a selected desired species ion of the plural species of ions taken out of the container by the taking out section onto an object to be processed; and

an electrically conductive mask located apart from the object to be processed and having openings formed to allow the selected desired species ion of the plural species of ions to pass through.

14. A semiconductor device manufacturing method comprising the steps of:

introducing a gas into a container in which a solid material including a plurality of elements is held;

converting the gas into a plasma in the container, irradiating the solid material with the plasma to thereby sputtering the solid material and generating ions of the plurality of elements;

trapping a plurality of elements in liquid form generated on the surface of the solid material during the step of generating the ions of the plurality of elements in a liquid trap;

taking the plural species of ions generated by the sputtering the solid material out of the container;

directing the plural species of ions taken out of the container toward an objected to be processed; and

irradiating a desired object to be processed with the directed plural species of ions.

15. An semiconductor device manufacturing method according to claim 14, wherein the melting point of the liquid is 800°

C. or below.

16. A semiconductor device manufacturing method comprising the steps of:

introducing an inert gas and a nitrogen gas into a container in which a material including a plurality of elements is held;

converting the inert gas and the nitrogen gas into plasmas in the container, irradiating the solid material with the plasmas of the inert gas and the nitrogen gas to thereby sputtering the solid material and generating ions of the plurality of elements;

nitriding a liquid including an element of the plurality of elements generated on the surface of the solid material during the step of generating the plurality of ions with the nitrogen gas;

taking the plural species of ions generated by the sputtering the solid material out of the container;

directing the plural species of ions taken out of the container toward an objected to be processed; and

irradiating a desired object to be processed with the directed plural species of ions.

17. An semiconductor device manufacturing method according to claim 16, wherein the melting point of the liquid is 800°

C. or below.

18. A semiconductor device manufacturing method according to claim 17, wherein the electrically conductive mask is made of one of the same element as the object to be processed and a material that consists mainly of that element.

19. A semiconductor device manufacturing method according to claim 18, wherein the electrically conductive mask is formed of one of the same element as the object to be processed and a material that consists mainly of that element.

20. A semiconductor device manufacturing method which comprises performing on an object to be processed a plurality of ion implantation steps that differ in at least one of ion species, acceleration energy, and implant dose, each of the ion implantation steps including, locating a conductive mask having openings formed apart from an object to be processed so that its openings are aligned with region of the object which are to be implanted with ions and implanting ions into the object through the conductive mask, the opening aligning with the regions of the object including a tapered structure in which a diameter increases in a direction away from the object to be processed.

21. A semiconductor device manufacturing method according to claim 20, further comprises the steps of carrying the object subjected to ion implantation in vacuum into thermal processing apparatus with vacuum kept, and carrying out thermal processing on the object in the thermal processing apparatus.

22. A semiconductor device manufacturing method including implanting p-type impurity ions into a first region of an object to be processed and n-type impurity ions into a second region of the object, comprising the steps of:

in implanting the p-type impurity ions, locating a first electrically conductive mask formed with an opening apart from the object so that the opening is aligned with the first region of the object and the second region is masked and implanting the p-type impurity ions into the object to be processed through the electrically conductive mask, the opening of the first electrically conductive mask aligning with the first region of the object including a tapered structure in which a diameter of the opening increases in a direction away from the object to be processed; and

in implanting the n-type impurity ions, locating a second electrically conductive mask formed with an opening apart from the object so that the opening is aligned with the second region of the object and the first region is masked and implanting the n-type impurity ions into the object to be processed through the electrically conductive mask, the opening of the second electrically conductive mask aligning with the second region of the object including a tapered structure in which a diameter of the opening increases in a direction away from the object to be processed.

23. A semiconductor device manufacturing method according to claim 22, further comprises the steps of carrying the object subjected to ion implantation in vacuum into thermal processing apparatus with vacuum kept, and carrying out thermal processing on the object in the thermal processing apparatus.

24. A method of manufacturing a semiconductor device having a first impurity region and a second impurity region which are implanted with impurities of opposite conductivity type, comprising the steps of:

introducing a gas into a container in which a solid material including a plurality of elements is held;

converting the gas into a plasma in the container, irradiating the solid material with the plasma to thereby sputtering the solid material and generating ions of the plurality of elements;

taking the plural species of ions generated by the sputtering the solid material out of the container;

irradiating a area of the surface of a semiconductor substrate with the first selected desired species ion of the plural of species of ions to thereby form the first impurity region in a region of the semiconductor substrate, in which the semiconductor device is to be formed; and

irradiating a area of the surface of a semiconductor substrate with the second selected desired species ion to thereby form the second impurity region in a region of the semiconductor substrate, in which the semiconductor device is to be formed.

25. An ion implantation apparatus comprising;

an electrically conductive mask having an opening and located apart from an object to be processed, side walls of said opening forming a tapered structure in which a diameter of the opening increases in a direction away from the object to be processed; and

an ion implanting section which implants ions into the object through the opening of the electrically conductive mask.

26. An ion implantation apparatus comprising:

an electrically conductive mask having an opening and located apart from an object to be processed, a distance between the electrically conductive mask and the object to be processed being less than 50 μ

m; and

an ion implanting section which implants ions into the object through the opening of the electrically conductive mask.

27. An ion implantation apparatus comprising:

an electrically conductive mask having an opening and located apart from an object to be processed, a surface of the electrically conductive mask formed of a material identical to a material mainly comprising the object to be processed; and

an ion implanting section which implants ions into the object through the opening of the electrically conductive mask.

28. A semiconductor device manufacturing method including implanting p-type impurity ions into a first region of an object to be processed and n-type impurity ions into a second region of the object, comprising the steps of:

in implanting the p-type impurity ions, locating a first electrically conductive mask formed with an opening apart from the object so that the opening is aligned with the first region of the object and the second region is masked apart from the object, a distance between the first conductive mask and the object to be processed being less than 50 μ

m, and implanting the p-type impurity ions into the object to be processed through the opening of the first electrically conductive mask; and

in implanting the n-type impurity ions, locating a second electrically conductive mask formed with an opening apart from the object so that the opening is aligned with the second region of the object and the first region is masked, a distance between the second conductive mask and the object to be processed being less than 50 μ

m, and implanting the n-type impurity ions into the object to be processed through the opening of the second electrically conductive mask.

29. A semiconductor device manufacturing method including implanting p-type impurity ions into a first region of an object to be processed and n-type impurity ions into a second region of the object, comprising the steps of:

in implanting the p-type impurity ions, locating a first electrically conductive mask formed with an opening apart from the object so that the opening is aligned with the first region of the object and the second region is masked and implanting the p-type impurity ions into the object to be processed through the opening of the first electrically conductive mask, a surface of the first electrically conductive mask being formed of a material identical to a material mainly comprising the object to be processed; and

in implanting the n-type impurity ions, locating a second electrically conductive mask formed with an opening apart from the object so that the opening is aligned with the second region of the object and the first region is masked and implanting the n-type impurity ions into the object to be processed through the opening of the second electrically conductive mask, a surface of the second electrically conductive mask being formed of a material identical to a material mainly comprising the object to be processed.

30. A semiconductor device manufacturing method which comprises performing on an object to be processed a plurality of ion implantation steps that differ in at least one of ion species, acceleration energy, and implant dose, each of the ion implantation steps including, locating a conductive mask having openings formed apart from an object to be processed so that its openings are aligned with regions of the object which are to be implanted with ions, and setting a distance between the conductive mask and the object to be processed less than 50 μ

m and implanting ions into the object through the conducive mask.

31. A semiconductor device manufacturing method which comprises performing on an object to be processed a plurality of ion implantation steps that differ, in at least one of ion species, acceleration energy, and implant dose, each of the ion implantation steps including, locating a conductive mask having openings and a surface formed of a material identical to a material mainly comprising the object to be processed apart from an object to be processed so that its openings are aligned with regions of the object which are to be implanted with ions and implanting ions into the object through the conductive mask.