Systems and methods for testing germanium devices
View Patent ↗Systems and methods are disclosed for a test device that is configured to allow assessment of the quality of germanium devices. In one embodiment, the test device is formed on the same substrate as the germanium devices, and includes a plurality of germanium components that are substantially similar to those found in the germanium devices. Such example measurement can used to estimate various quality parameters associated with fabrication of the germanium devices.
1. A semiconductor device structure comprising:
a plurality of functional semiconductor devices formed on a substrate, at least one of said functional semiconductor devices comprising a germanium component;
at least one test device formed on said substrate, said test device comprising at least one germanium test component, said germanium test component being substantially similar to said germanium component of said functional semiconductor devices, said germanium test component electrically connected between first and second contacts, and test pads electrically connected to said first and second test contacts;
wherein measurement of an electrical parameter associated with said test device via said test pads provides a measure of a quality of said functional semiconductor devices.
2. The apparatus of claim 1 , wherein said substrate comprises silicon.
3. The apparatus of claim 1 , wherein said plurality of functional semiconductor devices comprise resistors, diodes, or transistors.
4. The apparatus of claim 1 , wherein said at least one semiconductor device having said germanium component comprises an electro-optic device.
5. The apparatus of claim 4 , wherein said at least one germanium test component comprises an electro-optic device without an optical input.
6. The apparatus of claim 1 , wherein said at least one test device comprises a plurality of germanium test components.
7. The apparatus of claim 6 , wherein said germanium test components are connected in series.
8. The apparatus of claim 6 , wherein said test device comprises two or more test germanium components.
9. The apparatus of claim 8 , wherein said test device comprises ten or more test germanium components.
10. The apparatus of claim 9 , wherein said test device comprises 100 or more test germanium components.
11. The apparatus of claim 1 , wherein said germanium component comprises a silicon-germanium-silicon assembly having first and second silicon ends and a germanium region disposed therebetween, said first and second contacts associated with said first and second silicon ends respectively.
12. The apparatus of claim 1 , wherein said germanium component comprise a germanium-silicon-germanium assembly comprising first and second germanium regions with silicon disposed therebetween, said first and second contacts associated with said first and second germanium ends.
13. The apparatus of claim 1 , wherein said germanium component comprises a germanium-silicon assembly having a germanium end and a silicon end, said first contact associated with said germanium end and said second contact associated with said silicon end.
14. The apparatus of claim 1 , wherein said germanium test component comprises a germanium strip having first and second ends, said first and second test contacts formed with said first and second ends, respectively.
15. The apparatus of claim 14 , wherein said electrical parameter comprises a total resistance between the first and second test contacts.
16. The apparatus of claim 1 , wherein said germanium test component comprises first and second isolated germanium regions disposed on silicon, said first and second contacts formed with said first and second isolated germanium regions, respectively.
17. The apparatus of claim 16 , wherein said electrical parameter comprises a current between the first and second test contacts.
18. The apparatus of claim 1 , wherein said substrate comprises a wafer.
19. The apparatus of claim 18 , wherein said test device is formed on a portion of a scribe grid lane of said wafer.
20. The apparatus of claim 1 , wherein a plurality of said test devices are interspersed between said test pads, so that electrical measurement performed on two neighboring test pads measures an electrical property of one or more test devices between said two neighboring test pads.
21. An apparatus for testing a device having one or more germanium components formed on a substrate, comprising:
at least one germanium test component formed on said substrate, said test germanium component being substantially similar to said one or more germanium components, said at least one germanium test component electrically connected between first and second test contacts;
wherein measurement of an electrical parameter between said first and second test contacts provides a value that is indicative of a quality of said device.