Methods and Systems for Dopant Activation Using Microwave Radiation

• US 20200135468A1
• Filed: 12/24/2019
• Published: 04/30/2020
• Est. Priority Date: 08/09/2013
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Tsai, Chun-Hsiung, Yang, Huai-Tei, Yu, Kuo-Feng, Chen, Kei-Wei
• Granted Patent: US 10,923,355 B2
• Time in Patent Office: Days
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02584 Delta-doping
• CPC Class Codes: H01L 21/02694 Controlling the interface between substrate and epitaxial layer, e.g. by ion implantation followed by annealing
• CPC Class Codes: H01L 21/2252 using predeposition of impurities into the semiconductor surface, e.g. from a gaseous phase
• CPC Class Codes: H01L 21/2254 from or through or into an applied layer, e.g. photoresist, nitrides
• CPC Class Codes: H01L 21/2686 using incoherent radiation
• CPC Class Codes: H01L 21/324 Thermal treatment for modifying the properties of semiconductor bodies, e.g. annealing, sintering H01L21/20 - H01L21/288 and H01L21/302 - H01L21/322 take precedence
• CPC Class Codes: H01L 21/67115 mainly by radiation
• CPC Class Codes: H01L 21/76895 Local interconnects; Local pads, as exemplified by patent document EP0896365
• CPC Class Codes: H01L 29/0847 of field-effect transistors with insulated gate H01L29/0653 takes precedence; with a passive supplementary region between source or drain and substrate related to punch-through, capacity or isolation phenomena H01L29/1079; with LDD or DDD structure H01L29/7833; for thin film transistors H01L29/78618
• CPC Class Codes: H01L 29/167 further characterised by the doping material H01L29/1604 takes precedence
• CPC Class Codes: H01L 29/32 the imperfections being within the semiconductor body
• CPC Class Codes: H01L 29/45 Ohmic electrodes
• CPC Class Codes: H01L 29/66636 with source or drain recessed by etching or first recessed by etching and then refilled
• CPC Class Codes: H01L 29/66795 with a horizontal current flow in a vertical sidewall of a semiconductor body, e.g. FinFET, MuGFET
• CPC Class Codes: H01L 29/7848 the means being located in the source/drain region, e.g. SiGe source and drain
• CPC Class Codes: H01L 29/785 having a channel with a horizontal current flow in a vertical sidewall of a semiconductor body, e.g. FinFET, MuGFET
• CPC Class Codes: H01L 29/7851 with the body tied to the substrate
• CPC Class Codes: H05B 6/80 Apparatus for specific applications stoves or ranges F24C7/02

Abstract

A semiconductor structure includes a substrate, a source/drain (S/D) junction, and an S/D contact. The S/D junction is associated with the substrate and includes a trench-defining wall, a semiconductor layer, and a semiconductor material. The trench-defining wall defines a trench. The semiconductor layer is formed over the trench-defining wall, partially fills the trench, substantially covers the trench-defining wall, and includes germanium. The semiconductor material is formed over the semiconductor layer and includes germanium, a percentage composition of which is greater than a percentage composition of the germanium of the semiconductor layer. The S/D contact is formed over the S/D junction.

Claims

1-20. -20. (canceled)

21. A method comprising:

etching a source/drain trench in a substrate;

forming a first semiconductor layer in the source/drain trench, wherein the first semiconductor layer partially fills the source/drain trench;

forming a second semiconductor layer over the first semiconductor layer in the source/drain trench, wherein the second semiconductor layer fills a remaining portion of the source/drain trench, the first semiconductor layer includes a first concentration of a dopant, the second semiconductor layer includes a second concentration of the dopant, the second concentration of the dopant is different than the first concentration of the dopant, and the first semiconductor layer and the second semiconductor layer form a source/drain feature; and

activating the dopant by;

placing a microwave-absorption material a distance from the source/drain feature, and

applying microwave radiation to the microwave-absorption material and the source/drain feature.

22. The method of claim 21, wherein the distance is about 2 mm to about 10 mm.

23. The method of claim 21, wherein the applying the microwave radiation to the microwave-absorption material and the source/drain feature includes heating the substrate to a temperature of about 500°

C. to about 600°

C.

24. The method of claim 21, wherein the applying the microwave radiation to the microwave-absorption material and the source/drain feature includes heating the second semiconductor layer to a temperature of greater than about 1,100°

C.

25. The method of claim 21, wherein the microwave radiation has a frequency of about 2 GHz to about 10 GHz.

26. The method of claim 21, wherein the microwave radiation is applied to the microwave-absorption material and the source/drain feature for about 40 seconds to about 300 seconds.

27. The method of claim 21, wherein the placing the microwave-absorption material the distance from the source/drain feature includes placing the microwave-absorption material the distance above the second semiconductor layer.

28. The method of claim 21, wherein the microwave-absorption material includes a first microwave-absorption material and a second microwave-absorption material and the placing the microwave-absorption material the distance from the source/drain feature includes:

placing the first microwave-absorption material a first distance above the second semiconductor layer, and

placing the second microwave-absorption material a second distance below the second semiconductor layer.

29. The method of claim 21, wherein the first concentration of the dopant is the same before and after the applying the microwave radiation and the second concentration of the dopant is the same before and after the applying the microwave radiation.

30. The method of claim 21, further comprising, before applying the microwave radiation, pre-heating the microwave-absorption material.

31. A method comprising:

etching a source/drain trench in a substrate;

forming a first semiconductor layer in the source/drain trench, wherein the first semiconductor layer partially fills the source/drain trench;

forming a second semiconductor layer over the first semiconductor layer in the source/drain trench, wherein the second semiconductor layer fills a remaining portion of the source/drain trench, the first semiconductor layer includes a first concentration of a dopant, the second semiconductor layer includes a second concentration of the dopant, the second concentration of the dopant is different than the first concentration of the dopant, and the first semiconductor layer and the second semiconductor layer form a source/drain feature; and

activating the dopant by;

epitaxially growing a microwave-absorption material over the source/drain feature, and

after applying microwave radiation to the microwave-absorption material and the source/drain feature, removing the microwave-absorption material.

32. The method of claim 31, wherein a thickness of the microwave-absorption material is about 30 nm to about 250 nm.

33. The method of claim 31, wherein the applying the microwave radiation to the microwave-absorption material and the source/drain feature includes heating the substrate to a temperature of about 500°

C. to about 600°

C.

34. The method of claim 31, wherein the applying the microwave radiation to the microwave-absorption material and the source/drain feature includes heating the second semiconductor layer to a temperature of greater than about 1,100°

C.

35. The method of claim 31, wherein the microwave radiation has a frequency of about 2 GHz to about 10 GHz.

36. The method of claim 31, wherein the microwave radiation is applied to the microwave-absorption material and the source/drain feature for about 40 seconds to about 300 seconds.

37. The method of claim 31, wherein epitaxially growing the microwave-absorption material over the source/drain feature includes epitaxially growing the microwave-absorption material on the second semiconductor layer.

38. The method of claim 31, wherein the microwave-absorption material includes a first microwave-absorption material and a second microwave-absorption material and epitaxially growing the microwave-absorption material over the source/drain feature includes:

epitaxially growing the first microwave-absorption material on a surface of the second semiconductor layer, and

epitaxially growing the second microwave-absorption material on a surface of the substrate.

39. A method comprising:

etching a source/drain trench in a fin;

forming a first silicon-and-germanium-containing layer in the source/drain trench, wherein the first silicon-and-germanium-containing layer partially fills the source/drain trench;

forming a second silicon-and-germanium-containing layer over the first silicon-and-germanium-containing layer in the source/drain trench, wherein the second silicon-and-germanium-containing layer fills a remaining portion of the source/drain trench, the first silicon-and-germanium-containing layer includes a first concentration of boron, the second silicon-and-germanium-containing layer includes a second concentration of boron, the second concentration of boron is different than the first concentration of boron, and the first silicon-and-germanium-containing layer and the second silicon-and-germanium-containing layer form a source/drain feature; and

activating the boron by;

placing a microwave-absorption material a distance from the source/drain feature, and

applying microwave radiation to the microwave-absorption material and the source/drain feature.

40. The method of claim 39, wherein the first concentration of boron is the same before and after the applying the microwave radiation and the second concentration of boron is the same before and after the applying the microwave radiation.