HEAT TREATMENT METHOD FOR PROMOTING CRYSTALLIZATION OF HIGH DIELECTRIC CONSTANT FILM

• US 20130078786A1
• Filed: 09/10/2012
• Published: 03/28/2013
• Est. Priority Date: 09/26/2011
• Status: Active Grant

• Current Assignee: SCREEN Holdings Co., Ltd.
• Original Assignee: Kazuhiko Fuse, Shinichi Kato
• Inventors: FUSE, Kazuhiko, KATO, Shinichi
• Granted Patent: US 8,623,750 B2
• Time in Patent Office: Days
• US Class Current: 438/478
• CPC Class Codes: H01L 21/02356 treatment to change the morphology of the insulating layer, e.g. transformation of an amorphous layer into a crystalline layer
• CPC Class Codes: H01L 21/2686 using incoherent radiation
• CPC Class Codes: H01L 21/28176 with a treatment, e.g. annealing, after the formation of the definitive gate conductor
• CPC Class Codes: H01L 21/67115 mainly by radiation
• CPC Class Codes: H01L 21/68707 the wafers being placed on a robot blade, or gripped by a gripper for conveyance
• CPC Class Codes: H01L 21/68735 characterised by edge profile or support profile
• CPC Class Codes: H01L 29/513 the variation being perpendicular to the channel plane
• CPC Class Codes: H01L 29/517 the insulating material comprising a metallic compound, e.g. metal oxide, metal silicate H01L29/518 takes precedence
• CPC Class Codes: H01L 29/7848 the means being located in the source/drain region, e.g. SiGe source and drain

Abstract

A film of silicon dioxide is formed on the silicon-germanium layer, and a high dielectric constant film is further formed on the film of silicon dioxide. First irradiation from a flash lamp is performed on the semiconductor wafer to increase the temperature of a front surface of the semiconductor wafer from a preheating temperature to a target temperature for a time period in the range of 3 milliseconds to 1 second. Subsequently, second irradiation from the flash lamp is performed to maintain the temperature of the front surface of the semiconductor wafer within a ±25° C. range around the target temperature for a time period in the range of 3 milliseconds to 1 second. This promotes the crystallization of the high dielectric constant film while suppressing the alleviation of distortion in the silicon-germanium layer.

Claims

1. A method of heating a substrate including a high dielectric constant film formed on a silicon-germanium layer to promote the crystallization of said high dielectric constant film, said method comprising the steps of:

(a) forming a first silicon-germanium layer on a substrate, said first silicon-germanium layer including a second silicon-germanium layer with a first germanium concentration and third silicon-germanium layers with a second germanium concentration higher than said first germanium concentration, said second silicon-germanium layer being sandwiched between said third silicon-germanium layers;

(b) forming a film of silicon dioxide on said second silicon-germanium layer, and forming a high dielectric constant film on said film of silicon dioxide;

(c) heating said substrate including said high dielectric constant film formed thereon at a predetermined preheating temperature;

(d) irradiating said substrate with light to increase the temperature of a front surface of said substrate from said preheating temperature to a target temperature for a time period in the range of 3 milliseconds to 1 second; and

(e) irradiating said substrate with light to maintain the temperature of the front surface of said substrate within a ±

25°

C. range around said target temperature for a time period in the range of 3 milliseconds to 1 second, said step (e) being performed after said step (d).

2. The method according to claim 1, wherein

said preheating temperature is in the range of 600°

C. to 900°

C., and

said target temperature is in the range of 1000°

C. to 1200°

C.

3. The method according to claim 1, wherein

said substrate is irradiated with a flash of light from a flash lamp in said step (d) and in said step (e).

4. The method according to claim 3, wherein

a switching element intermittently supplies electrical charges from a capacitor to said flash lamp to control an emission output from said flash lamp in said step (d) and in said step (e).

5. The method according to claim 4, wherein

the electrical charges are intermittently supplied from said capacitor to said flash lamp by applying a plurality of pulses to the gate of said switching element.

6. The method according to claim 5, wherein

said switching element is an insulated-gate bipolar transistor.

7. The method according to claim 1, wherein

a gate electrode including at least one metal selected from the group consisting of titanium, zirconium, hafnium, vanadium, niobium, tantalum, molybdenum, and tungsten is formed on said high dielectric constant film.

8. The method according to claim 1, wherein

said high dielectric constant film includes at least one selected from the group consisting of TiN, ZrN, HfN, VN, NbN, TaN, MoN, WN, TiSiN, HfSiN, VSiN, NbSiN, TaSiN, MoSiN, WSiN, HfAlN, VAlN, NbAlN, TaAlN, MoAlN, and WAlN.