Array of vertical transistors and method used in forming an array of vertical transistors

Patent metadata

Field	Value
Publication number	US-11488981-B2
Application number	US-202016934607-A
Country	US
Kind code	B2
Filing date	Jul 21, 2020
Priority date	Jul 21, 2020
Publication date	Nov 1, 2022
Grant date	Nov 1, 2022

Abstract

An array of vertical transistors comprises spaced pillars of individual vertical transistors that individually comprise an upper source/drain region, a lower source/drain region, and a channel region vertically there-between. The upper source/drain region comprises a conductor oxide material in individual of the pillars. The channel region comprises an oxide semiconductor material in the individual pillars. The lower source/drain region comprises a first conductive oxide material in the individual pillars atop and directly against a second conductive oxide material in the individual pillars. Horizontally-elongated and spaced conductor lines individually interconnect a respective multiple of the vertical transistors in a column direction. The conductor lines individually comprise the second conductive oxide material atop and directly against metal material. The first conductive oxide material, the second conductive oxide material, and the metal material comprise different compositions relative one another. The second conductive oxide material of the conductor lines is below and directly against the second conductive oxide material of the lower source/drain region of the individual pillars of the respective multiple vertical transistors. Horizontally-elongated and spaced conductive gate lines are individually operatively aside the oxide semiconductor material of the channel region of the individual pillars and individually interconnect a respective plurality of the vertical transistors in a row direction. A conductive structure is laterally-between and spaced from immediately-adjacent of the spaced conductor lines in the row direction. The conductive structures individually comprise a top surface that is higher than a top surface of the metal material of the conductor lines. Other embodiments, including method, are disclosed.

First claim

The invention claimed is:

1. An array of vertical transistors, comprising:
spaced pillars of individual vertical transistors; the spaced pillars individually comprising an upper source/drain region, a lower source/drain region, and a channel region vertically there-between; the upper source/drain region comprising a conductor oxide material in individual of the pillars, the channel region comprising an oxide semiconductor material in the individual pillars, the lower source/drain region comprising a first conductive oxide material in the individual pillars atop and directly against a second conductive oxide material in the individual pillars;
horizontally-elongated and spaced conductor lines that individually interconnect a respective multiple of the vertical transistors in a column direction, the conductor lines individually comprising the second conductive oxide material atop and directly against metal material; the first conductive oxide material, the second conductive oxide material, and the metal material comprising different compositions relative one another; the second conductive oxide material of the conductor lines being below and directly against the second conductive oxide material of the lower source/drain region of the individual pillars of the respective multiple vertical transistors;
horizontally-elongated and spaced conductive gate lines individually operatively aside the oxide semiconductor material of the channel region of the individual pillars and that individually interconnect a respective plurality of the vertical transistors in a row direction; and
a conductive structure laterally-between and spaced from immediately-adjacent of the spaced conductor lines in the row direction, the conductive structures individually comprising a top surface that is higher than a top surface of the metal material of the conductor lines.

2. The array of claim 1 wherein the conductive structures in operation function as parasitic-capacitance buffers between the immediately-adjacent conductor lines.

3. The array of claim 1 wherein the conductive structures directly electrically couple to a common conductor that is spaced below the conductor lines.

4. The array of claim 1 wherein the first conductive oxide material in the individual pillars is thicker than the second conductive oxide material in the individual pillars.

5. The array of claim 1 wherein the second conductive oxide material of the conductor lines and the second conductive oxide material of the lower source/drain region of the individual pillars are of the same thickness relative one another.

6. The array of claim 1 wherein the metal material in the conductor lines is thicker than the second conductive oxide material in the conductor lines.

7. The array of claim 1 wherein the metal material comprises at least one of an elemental metal, an alloy of elemental metals, or a conductive metal nitride.

8. The array of claim 1 wherein the metal material is devoid of any detectable conducting oxide.

9. The array of claim 1 wherein the conductive structures are conductive lines that are horizontally-elongated in the column direction along the immediately-adjacent conductor lines.

10. The array of claim 1 wherein the conductive structures are conductive pillars that are spaced relative one another in the column direction along the immediately-adjacent conductor lines.

11. The array of claim 1 wherein the oxide semiconductor material comprises one or more of Zn x Sn y O, In x Zn y O, Zn x O, In x Ga y Zn z O, In x Ga y Si z O a , In x W y O, In x O, Sn x O, Ti x O, Zn x ON z , Mg x Zn y O, Zr x In y Zn z O, Hf x In y Zn z O, Sn x In y Zn z O, Al x Sn y In z Zn a O, Si x In y Zn z O, Al x Zn y Sn z O, Ga x Zn y Sn z O, Zr x Zn y Sn z O, and In x Ga y Si z O.

12. The array of claim 1 wherein the first and second conductive oxide materials comprise at least one of indium tin oxide, indium oxide, tin oxide, zinc oxide, titanium oxide, and ruthenium oxide.

13. The array of claim 1 wherein the conductor oxide material of the upper source/drain region comprises a first conductor oxide material above and directly against a second conductor oxide material, the first and second conductor oxide materials comprising different compositions relative one another.

14. The array of claim 13 wherein the first conductor oxide material and the second conductive oxide material are of the same composition relative one another.

15. The array of claim 13 wherein the second conductor oxide material and the first conductive oxide material are of the same composition relative one another.

16. The array of claim 13 wherein,
the first conductor oxide material and the second conductive oxide material are of the same composition relative one another; and
the second conductor oxide material and the first conductive oxide material are of the same composition relative one another.

17. The array of claim 13 wherein the first and second conductor oxide materials comprise at least one of indium tin oxide, indium oxide, tin oxide, zinc oxide, titanium oxide, and ruthenium oxide.

18. The array of claim 1 wherein the vertical transistors comprise individual memory cells of a memory array.

19. The array of claim 1 comprising a plurality of memory elements that are individually directly electrically coupled to individual of the upper source/drain regions of the individual pillars.

20. An array of vertical transistors, comprising:
spaced pillars of individual vertical transistors; the spaced pillars individually comprising an upper source/drain region above a channel region, the upper source/drain region comprising a conductor oxide material in individual of the pillars, the channel region comprising an oxide semiconductor material in the individual pillars;
horizontally-elongated and spaced conductor lines that individually interconnect a respective multiple of the vertical transistors in a column direction; the conductor lines individually comprising a first conductive oxide material, a second conductive oxide material, and a metal material; the first conductive oxide material, the second conductive oxide material, and the metal material comprising different compositions relative one another; the first conductive oxide material in the conductor lines being atop and directly against the second conductive oxide material in the conductor lines, the second conductive oxide material in the conductor lines being atop and directly against the metal material in the conductor lines, the first conductive oxide material of the conductor lines being below and directly against the oxide semiconductor material of the channel regions of the individual pillars of the respective multiple vertical transistors;
horizontally-elongated and spaced conductive gate lines individually operatively aside the oxide semiconductor material of the channel region of the individual pillars and that individually interconnect a respective plurality of the vertical transistors in a row direction; and
a conductive structure laterally-between and spaced from immediately-adjacent of the spaced conductor lines in the row direction, the conductive structures individually comprising a top surface that is higher than a top surface of the metal material of the conductor lines.

21. The array of claim 20 wherein the second conductive oxide material in the conductor lines is thicker than the first conductive oxide material in the conductor lines.

22. The array of claim 20 wherein the top surfaces o

Assignees

• Micron Technology Inc

Inventors

• Lee Yi Fang
• Guha Jaydip
• Heineck Lars P
• Karda Kamal M
• Lee Si-Woo
• Mcdaniel Terrence B
• Sills Scott E
• Torek Kevin J
• Yang Sheng-Wei

Classifications

• H01L21/84

  Electricity · mapped topic

• H01L27/1255

  Electricity · mapped topic

• H01L27/1203

  Electricity · mapped topic

• H01L27/127

  Electricity · mapped topic

• H01L27/124

  Electricity · mapped topic