System and method for mitigating oxide growth in a gate dielectric

Patent metadata

Field	Value
Publication number	US-10068771-B2
Application number	US-201815865758-A
Country	US
Kind code	B2
Filing date	Jan 9, 2018
Priority date	May 13, 2003
Publication date	Sep 4, 2018
Grant date	Sep 4, 2018

Abstract

Oxide growth of a gate dielectric layer that occurs between processes used in the fabrication of a gate dielectric structure can be reduced. The reduction in oxide growth can be achieved by maintaining the gate dielectric layer in an ambient effective to mitigate oxide growth of the gate dielectric layer between at least two sequential process steps used in the fabrication the gate dielectric structure. Maintaining the gate dielectric layer in an ambient effective to mitigate oxide growth also improves the uniformity of nitrogen implanted in the gate dielectric.

First claim

What is claimed is:

1. A method for forming a device structure on a substrate, comprising:
introducing the substrate to a processing system by transferring the substrate through a load lock to a distinct transfer chamber, the transfer chamber having a gas distribution system in fluid communication with the transfer chamber and a first pumping element connected to the transfer chamber;
maintaining the transfer chamber at a first pressure while actively purging the transfer chamber with an inert gas using the gas distribution system and the first pumping element;
while maintaining the transfer chamber at the first pressure and actively purging the transfer chamber, transferring the substrate to a process chamber having a distinct second pumping element;
forming a gate dielectric over the substrate in the process chamber;
forming a gate electrode over the gate dielectric; and
forming first and second doped regions on opposite sides of the gate electrode; and
after forming the gate dielectric, transferring the substrate through the transfer chamber to the load lock while actively purging the transfer chamber.

2. The method of claim 1 , further comprising heating the substrate in the process chamber.

3. The method of claim 1 , further comprising performing a process with an oxygen source on the substrate.

4. The method of claim 1 , wherein the step of forming the gate dielectric further comprises maintaining a second pressure in the process chamber using the second pumping element connected to the process chamber.

5. The method of claim 1 , wherein the gate electrode is a metal gate electrode.

6. The method of claim 5 , wherein the first and second doped regions are formed after forming the gate electrode.

7. The method of claim 1 , further comprising annealing the substrate after forming the gate dielectric.

8. The method of claim 1 , wherein the processing system comprises at least one additional process chamber.

9. A method for forming a device structure on a substrate, comprising:
forming a gate dielectric comprising hafnium oxide by:
introducing the substrate to a processing system by transferring the substrate through a load lock to a distinct transfer chamber, the transfer chamber having a gas distribution system in fluid communication with the transfer chamber and a first pumping element connected to the transfer chamber;
maintaining the transfer chamber at a first pressure while actively purging the transfer chamber with an inert gas using the gas distribution system and the first pumping element;
while maintaining the transfer chamber at the first pressure and actively purging the transfer chamber, transferring the substrate to a process chamber having a distinct second pumping element; and
forming the hafnium oxide over the substrate in the process chamber while maintaining a second pressure in the process chamber using the second pumping element connected to the process chamber;

forming a gate electrode on the gate dielectric; and
forming first and second doped regions on opposite sides of the gate electrode.

10. The method of claim 9 , wherein the gate electrode is a metal gate electrode.

11. The method of claim 10 , wherein the first and second doped regions are formed after forming the gate electrode.

12. The method of claim 9 , further comprising heating the substrate in the process chamber.

13. The method of claim 9 , further comprising performing a process with an oxygen source on the substrate.

14. The method of claim 9 , further comprising annealing the substrate after forming the gate dielectric.

15. A transistor device having a gate dielectric, a gate electrode, a first doped region and a second doped region, wherein the gate dielectric is formed by a process comprising the steps of:
forming a hafnium oxide layer over a substrate in a process chamber of a processing system, the process chamber having a first pumping element configured to evacuate gas from the process chamber;
performing a process on the substrate with an oxygen source; and
transferring the substrate between a load lock and the process chamber through a transfer chamber of the processing system, wherein the transfer chamber is connected to the process chamber, the transfer chamber having a gas distribution system and a second, distinct pumping element that maintain a first pressure in the transfer chamber and actively purge the transfer chamber by flowing an inert gas during the transferring of the substrate between the load lock and the process chamber.

16. The transistor device of claim 15 , wherein the oxygen source is O 2 , N 2 O, or NO and the process is performed at a temperature in the range of 400° C. to 1200° C.

17. The transistor device of claim 15 , wherein the gate electrode a metal gate electrode.

18. The transistor device of claim 15 , wherein the inert gas is flowed at a rate of 2 liters per minute to 7 liters per minute.

19. The transistor device of claim 18 , wherein the inert gas is N 2 and the first pressure is about 3 Torr to about 200 Torr in the transfer chamber during the transferring.

Assignees

• Texas Instruments Inc

Inventors

• Bevan Malcolm J
• Bu Haowen
• Niimi Hiroaki
• Alshareef Husam N

Classifications

• H10P14/69392

  the material containing hafnium, e.g. HfO2 · CPC title

• H10P14/6339

  deposition by cyclic CVD, e.g. ALD, ALE or pulsed CVD · CPC title

• H10P14/6322

  Formation by thermal treatments (formation by plasma treatment H10P14/6319) · CPC title

• H10P14/6319

  Formation by plasma treatments, e.g. plasma oxidation of the substrate · CPC title

• H10P95/90

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