Low temperature zirconia based thermal barrier layer by PVD

• US 20030134054A1
• Filed: 11/08/2002
• Published: 07/17/2003
• Est. Priority Date: 11/09/2001
• Status: Active Grant

• Current Assignee: Demaray LLC
• Original Assignee: Springworks, LLC (Petters Group Worldwide LLC)
• Inventors: Demaray, Richard E., Milonopoulou, Vassiliki
• Granted Patent: US 7,404,877 B2
• Time in Patent Office: Days
• US Class Current: 427/595
• CPC Class Codes: C23C 14/083 of refractory metals or yttrium
• CPC Class Codes: C23C 14/3414 Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy

Abstract

Formation of a zirconia based thermal barrier layer is described. In accordance with the present invention, a thermal barrier layer composed of zirconia or an allow of zirconia is presented. An advantageous layer might be composed of zirconia or an alloy of zirconia with silica having improved properties. In some embodiments, such a zirconia layer might be deposited with a fraction of it'"'"'s zirconia in a metallic state. Such a fraction, particularly if it were very low, would act to nucleate crystalline grains of silicon during the recrystallization phase of excimer laser melting due to the formation of point defects of zirconium silicide or other nucleating compound or formation. Heat treating the Zirconia layer anneals the Zirconia layer so that it can act as a gate oxide.

Claims

1. A method of forming a thermal barrier layer, comprising:

forming a target of zirconia;

depositing a zirconia layer in a PVD chamber from the target.

2. The method of claim 1, wherein forming the target includes

mixing zirconia powder with between 8 and 12% yttria powder;

and

isostatic pressing the mixed powder.

3. The method of claim 1, wherein forming the target includes

mixing zirconium metal with about 8 to about 12% yttria metal powder;

and

hipping the mixed powder.

4. The method of claim 2, wherein depositing a zirconia layer includes

applying about 4 to about 6 kW of 13.56 MHz of RF power on a target cathode of the PVD chamber;

applying about 4 to about 6 mTorr of system pressure in the PVD chamber; and

applying about 200 to about 600 watts of bias power at about 2 MHz to a substrate on which the zirconia layer will be deposited.

5. The method of claim 4, further including

adding between about 60 and about 80 sccm of oxygen to the PVD chamber;

and

adding between about 40 and about 20 sccm of Argon to the PVD chamber, wherein the total gas flow is about 100 sccm.

6. The method of claim 3, wherein depositing a zirconia layer includes

applying between about 4 and about 8 kW of 200 MHz pulsed DC power on the target;

applying between about 3 and about 6 mTorr of system pressure to the PVD chamber;

applying about 200 to about 600 Watts at 2 MHz of bias power to the substrate on which the zirconia layer will be deposited.

7. The method of claim 6, further including

adding between about 60 and about 80 seem of oxygen to the PVD chamber;

and

adding between about 40 and about 20 sccm of Argon to the PVD chamber, wherein the total gas flow is about 100 sccm.