Apparatus with doped surfaces, and related methods with in situ doping

Patent metadata

Field	Value
Publication number	US-11088147-B2
Application number	US-201916453788-A
Country	US
Kind code	B2
Filing date	Jun 26, 2019
Priority date	Jun 26, 2019
Publication date	Aug 10, 2021
Grant date	Aug 10, 2021

Abstract

Apparatus, such as electronic devices and structures thereof, include at least one doped surface of a base (e.g., semiconductor) material. A dopant of the at least one doped surface is concentrated along the surface, defining a thickness, on or in the base material, not exceeding about one atomic layer. Methods for forming the doped surfaces involve gas-phase doping exposed surfaces of the base material in situ, within a same material-removal tool used to form at least one opening defined at least partially by the base material and into which the dopant is to be introduced.

First claim

What is claimed is:

1. An apparatus, comprising:
an access line extending into a base material, the access line separating a first region defined in the base material from a second region defined in the base material;
a digit line extending through at least one dielectric material to the first region;
a contact extending through the at least one dielectric material to the second region; and
at least one doped surface of the base material, the at least one doped surface extending along at least a portion of one or more of the access line, the digit line, and the contact, the at least one doped surface comprising a dopant at a thickness not exceeding about one atomic layer.

2. The apparatus of claim 1 , wherein the at least one doped surface comprises a doped surface extending, along a wall of the access line, between the first region and the second region.

3. The apparatus of claim 2 , wherein the at least one doped surface further comprises another doped surface along an upper surface of the first region.

4. The apparatus of claim 3 , wherein the at least one doped surface further comprises an additional doped surface along an upper surface of the second region.

5. The apparatus of claim 1 , wherein the contact consists of one conductive material.

6. The apparatus of claim 1 , wherein the contact comprises a conductive material within a polysilicon material.

7. The apparatus of claim 1 , wherein the dopant comprises at least one of boron, phosphorous, indium, or arsenic.

8. The apparatus of claim 1 , further comprising a third region separated from the first region by another access line.

9. The apparatus of claim 1 , wherein the apparatus is a memory device.

10. The apparatus of claim 9 , wherein the memory device is a dynamic random access memory (DRAM) device.

11. A method of forming an apparatus, comprising:
within a material-removing tool, removing at least one portion of a base material to define at least one opening in the base material;
also within the material-removing tool, doping exposed surfaces of the base material defining the at least one opening with a dopant to incorporate the dopant on or into the base material to form at least one doped surface of the base material, the at least one doped surface comprising the dopant at a thickness not exceeding about one atomic layer;
forming an access line in the at least one opening, the access line extending into the base material, the access line separating a first region defined in the base material from a second region defined in the base material;
forming at least one dielectric material above the access line;
forming a digit line extending through the at least one dielectric material to the first region; and
forming a contact extending through the at least one dielectric material to the second region,
wherein the at least one doped surface extends along at least a portion of the access line.

12. The method of claim 11 , wherein the doping follows completion of the removing of the at least one portion of the base material.

13. The method of claim 12 , wherein a width of each of the at least one opening following the completion of the removing of the at least one portion of the base material remains the width following the doping.

14. The method of claim 11 , wherein the doping comprises gas-phase doping.

15. The method of claim 11 :
further comprising, before removing the at least one portion of the base material, forming a doped region within the base material;
wherein removing the at least one portion of the base material to define the at least one opening in the base material comprises defining access lines trenches through the doped region to define the first region and the second region; and
wherein doping the exposed surfaces of the base material defining the at least one opening with the dopant comprises exposing vertical sidewalls of the first region and the second region to a precursor gas comprising the dopant.

16. The method of claim 11 , further comprising, after the doping and before forming the access line in the at least one opening, forming a first dielectric material directly on at least some of the exposed surfaces of the base material to activate the dopant incorporated on or into the base material.

17. The method of claim 16 , wherein forming the access line in the at least one opening comprises forming a gate region within the first dielectric material.

18. The method of claim 11 , wherein forming the contact extending through the at least one dielectric material to the second region comprises:
forming an additional opening through the at least one dielectric material to expose an additional surface of the second region in the additional opening;
doping, with an additional dopant, the additional surface of the second region to incorporate the additional dopant on or into the second region to form an additional doped surface of the second region; and
after the doping of the additional surface of the second region, forming a conductive material directly on the additional doped surface of the second region to substantially fill the additional opening.

19. The method of claim 18 , wherein forming the conductive material directly on the additional doped surface of the second region is not preceded by forming another material directly on the additional doped surface of the second region.

20. A method of doping surfaces of a structure for an apparatus, comprising:
introducing, to a dry etching tool, a structure comprising a base material;
within the dry etching tool:
introducing an etchant gas to remove at least one portion of the base material to define therein at least one opening; and
introducing a precursor gas comprising a dopant to incorporate the dopant into exposed surfaces of the base material; and

exposing the dopant to heat to form a doped surface along the exposed surfaces of the base material, the dopant extending into the base material at a depth not exceeding about one atomic layer;
forming, in the at least one opening, an access line extending into the base material, the access line separating a first region defined in the base material from a second region defined in the base material;
forming at least one dielectric material above the access line;
forming a digit line extending through the at least one dielectric material to the first region; and
forming a contact extending through the at least one dielectric material to the second region,
wherein the doped surface extends along at least a portion of the access line, the doped surface comprising the dopant at a thickness not exceeding the about one atomic layer.

21. The method of claim 20 , wherein introducing the precursor gas comprising the dopant comprises introducing a volatile boron-comprising gas or a volatile arsenic-comprising gas.

22. The method of claim 20 , wherein introducing the etchant gas and introducing the precursor gas comprise introducing the precursor gas while introducing the etchant gas.

23. An apparatus, comprising:
at least one memory device comprising:
at least one doped surface of a base material; and
at least one access transistor comprising a source region and a drain region,
the at least one doped surface comprising a dopant concentrated at a continuous doped surface extending directly between the source region and the drain region, the continuous doped surface defining a thickness of the dopant of less than about one atomic layer.

Assignees

• Micron Technology Inc

Inventors

• Guha Jaydip
• Keshav Saurabh
• Pulugurtha Srinivas
• Akhtar Mohd Kamran
• Franek James B
• Schrinsky Alex J

Classifications

• H10P95/90

  Thermal treatments, e.g. annealing or sintering · CPC title

• H10P50/20

  Dry etching; Plasma etching; Reactive-ion etching · CPC title

• H10P32/171

  being group IV material · CPC title

• H10P32/12 Primary

  between a solid phase and a gaseous phase · CPC title

• H01L27/10891

  Electricity · mapped topic