HIGH CONCENTRATION WATER PULSES FOR ATOMIC LAYER DEPOSITION

• US 20110053383A1
• Filed: 08/26/2009
• Published: 03/03/2011
• Est. Priority Date: 08/26/2009
• Status: Active Grant

• Current Assignee: ASM IP Holding B.V. (ASM International NV)
• Original Assignee: ASM America Incorporated (ASM International NV)
• Inventors: Verghese, Mohith, Shero, Eric J., Maes, Jan Willem
• Granted Patent: US 9,117,773 B2
• Time in Patent Office: Days
• US Class Current: 438/765
• CPC Class Codes: C23C 16/405 of refractory metals or yttrium
• CPC Class Codes: C23C 16/45527 characterized by the ALD cycle, e.g. different flows or temperatures during half-reactions, unusual pulsing sequence, use of precursor mixtures or auxiliary reactants or activations
• CPC Class Codes: H01L 21/02181 the material containing hafnium, e.g. HfO2
• CPC Class Codes: H01L 21/02189 the material containing zirconium, e.g. ZrO2
• CPC Class Codes: H01L 21/02192 the material containing at least one rare earth metal element, e.g. oxides of lanthanides, scandium or yttrium
• CPC Class Codes: H01L 21/02194 the material containing more than one metal element
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/3141 Deposition using atomic layer deposition techniques [ALD]
• CPC Class Codes: H01L 21/31645 Deposition of Hafnium oxides, e.g. HfO2

Abstract

Methods are provided herein for forming thin films comprising oxygen by atomic layer deposition. The thin films comprising oxygen can be deposited by providing higher concentration water pulses, a higher partial pressure of water in the reaction space, and/or a higher flow rate of water to a substrate in a reaction space. Thin films comprising oxygen can be used, for example, as dielectric oxides in transistors, capacitors, integrated circuits, and other semiconductor applications.

Claims

1. A method for forming a thin film comprising oxygen on a substrate in a reaction space by atomic layer deposition, the method comprising a deposition cycle comprising:

providing a vapor phase reactant pulse of a first reactant comprising hafnium and/or zirconium to the reaction space such that it forms no more than a monolayer of first reactant on the substrate surface;

removing excess first reactant from the reaction space;

providing a vapor phase reactant pulse of a second reactant comprising water to the reaction space, such that the partial pressure of water in the reaction space is greater than about 100 mTorr; and

removing excess second reactant and any reaction byproducts from the reaction space.

2. The method of claim 1, wherein the deposition cycle is repeated until a thin film of a desired thickness is obtained.

3. The method of claim 1, wherein the first reactant further comprises an element from the group consisting of:

Ti, Al, and Si.

4. The method of claim 3, wherein the first reactant comprises a chloride.

5. The method of claim 4, wherein the first reactant comprises HfCl₄ or ZrCl₄.

6. The method of claim 5, wherein the first reactant is HfCl₄ and HfO₂ is deposited.

7. The method of claim 1, wherein the partial pressure of water in the reaction space is greater than about 250 mTorr.

8. The method of claim 1, wherein the partial pressure of water in the reaction space is greater than about 500 mTorr.

9. The method of claim 1, wherein the partial pressure of water in the reaction space is greater than about 1000 mTorr.

10. The method of claim 1, wherein the deposition cycle deposits greater than about 20% of a monolayer per cycle.

11. The method of claim 1, wherein the substrate temperature during the deposition cycle is above about 250°

C.

12. The method of claim 1, wherein providing a vapor phase pulse of water comprises a pulse length of about 100 ms or higher.

23. The method of claim 1, wherein the thin film comprising oxygen further comprises one or more elements from the group consisting of La, Ce, Pr, Nd, Pm, Sm, Er, Gd, Tb, Dy, Ho, Tm, Yb, Lu, Ba, and Sr

13. A method for forming a thin film comprising oxygen by atomic layer deposition on a substrate in a reaction space comprising:

alternately and sequentially providing a vapor phase reactant pulse comprising a precursor comprising chlorine and hafnium;

chlorine and zirconium;

or chlorine and hafnium and zirconium and a vapor phase reactant pulse comprising water to the reaction space;

wherein the vapor phase reactant pulses are repeated until a thin film of a desired thickness is obtained,

wherein the vapor phase reactant pulse comprising water is provided such that the partial pressure of water in the reaction space is greater than about 200 mTorr.

14. The method of claim 13, wherein the partial pressure of water in the reaction space is greater than about 1500 mTorr.

15. The method of claim 14, wherein the partial pressure of water in the reaction space is greater than about 2500 mTorr.

21. The method of claim 13, wherein the thin film comprising oxygen comprises HfO₂ or ZrO₂.

24. The method of claim 13, wherein the thin film comprising oxygen further comprises one or more elements from the group consisting of La, Ce, Pr, Nd, Pm, Sm, Er, Gd, Tb, Dy, Ho, Tm, Yb, Lu, Ba, and Sr.

16. (canceled)

17. A process for forming a thin film by atomic layer deposition on a substrate in a reaction space comprising:

alternately and sequentially contacting a substrate with a vapor phase reactant pulse comprising a first precursor comprising hafnium and/or zirconium and a vapor phase reactant pulse comprising water, wherein the water is provided such that the partial pressure of water in the reaction space is greater than about 250 mTorr; and

repeating the alternate and sequential pulses until a thin film of a desired thickness is obtained.

18. The method of claim 17, wherein the partial pressure of water in the reaction space is greater than about 500 mTorr.

19. The method of claim 17, wherein the partial pressure of water in the reaction space is greater than about 2000 mTorr.

22. The method of claim 17, wherein the thin film comprising oxygen comprises HfO₂ or ZrO₂.

25. The method of claim 17, wherein the thin film comprising oxygen further comprises one or more elements from the group consisting of La, Ce, Pr, Nd, Pm, Sm, Er, Gd, Tb, Dy, Ho, Tm, Yb, Lu, Ba, and Sr.

20. (canceled)