Biased pulse DC reactive sputtering of oxide films

• US 7,413,998 B2
• Filed: 09/16/2005
• Issued: 08/19/2008
• Est. Priority Date: 03/16/2002
• Status: Expired due to Term

• Current Assignee: Demaray LLC
• Original Assignee: Springworks, LLC (Petters Group Worldwide LLC)
• Inventors: Narasimhan, Mukundan, Mullapudi, Ravi B., Demaray, Richard E., Zhang, Hongmei
• Primary Examiner(s): MANDALA, MICHELLE
• Application Number:
  US11/228,717
• Publication Number:
  US 20060057283A1
• Time in Patent Office: 1,068 Days
• Field of Search: 438/769, 438/770, 438/771, 438/787, 438/788, 438/533, 257/E21.273, 257/E21.278, 257/E21.462, 204/192.12, 204/192.15
• US Class Current: 438/769
• CPC Class Codes: C23C 14/0036 Reactive sputtering
• CPC Class Codes: C23C 14/081 of aluminium, magnesium or beryllium
• CPC Class Codes: C23C 14/10 Glass or silica
• CPC Class Codes: C23C 14/3414 Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy
• CPC Class Codes: C23C 14/345 using substrate bias
• CPC Class Codes: C23C 14/35 by application of a magnetic field, e.g. magnetron sputtering C23C14/3457 takes precedence
• CPC Class Codes: C23C 14/354 Introduction of auxiliary energy into the plasma
• CPC Class Codes: C23C 14/5806 Thermal treatment
• CPC Class Codes: C23C 14/5873 Removal of material
• CPC Class Codes: G02B 6/132 by deposition of thin films
• CPC Class Codes: H01J 37/32412 Plasma immersion ion implantation
• CPC Class Codes: H01J 37/34 operating with cathodic sputtering H01J37/36 takes precedence ; methods of cathodic sputtering C23C14/34

Abstract

A biased pulse DC reactor for sputtering of oxide films is presented. The biased pulse DC reactor couples pulsed DC at a particular frequency to the target through a filter which filters out the effects of a bias power applied to the substrate, protecting the pulsed DC power supply. Films deposited utilizing the reactor have controllable material properties such as the index of refraction. Optical components such as waveguide amplifiers and multiplexers can be fabricated using processes performed on a reactor according to the present invention.

Claims

1. A method of forming a waveguide amplifier, comprising:

providing a substrate with an undercladding layer;

providing an RF bias to the substrate;

providing a target having a concentration of rare-earth ions opposite the substrate;

supplying process gas between the target and the substrate;

applying pulsed DC power where the voltage on the target oscillates between positive and negative voltages through a narrow band rejection filter that matches the RF bias to the target to deposit an optically active film;

patterning the film to form a core;

depositing an uppercladding layer over the core.

2. The method of claim 1, wherein providing a substrate includes providing a silicon substrate with a thermal oxide layer.

3. The method of claim 1, wherein providing a target includes providing a target having a concentration of up to about 5 cat. % of rare earth ions.

4. The method of claim 3, wherein providing a target includes providing a target of Al and Si.

5. The method of claim 1, wherein providing a target includes providing a target with a concentration of Al.

6. The method of claim 5, wherein providing a target includes providing a target with a concentration of Si.

7. The method of claim 5, wherein providing a target includes providing a target with a concentration of rare earth ions.

8. The method of claim 1, further including providing bias power to the substrate.

9. The method of claim 1, further including scanning a magnet over the target.

10. The method of claim 1, wherein scanning the magnet over the target includes moving the magnet in a first direction.

11. The method of claim 10, wherein the magnet extends beyond the target in a second direction perpendicular to the first direction.

12. The method of claim 1, wherein the target has a surface area greater than the surface area of the substrate.

13. The method of claim 8, wherein the filter rejects power at a frequency of the bias power.