US 11,935,838 B2
Method and system for fabricating fiducials using selective area growth
Clifford Drowley, Santa Clara, CA (US); Ray Milano, Santa Clara, CA (US); Robert Routh, Santa Clara, CA (US); Subhash Srinivas Pidaparthi, Santa Clara, CA (US); and Andrew P. Edwards, Santa Clara, CA (US)
Assigned to Nexgen Power Systems, Inc., Santa Clara, CA (US)
Filed by NexGen Power Systems, Inc., Santa Clara, CA (US)
Filed on Mar. 29, 2022, as Appl. No. 17/707,833.
Application 17/707,833 is a continuation of application No. 16/929,896, filed on Jul. 15, 2020, granted, now 11,315,884.
Claims priority of provisional application 62/875,443, filed on Jul. 17, 2019.
Prior Publication US 2022/0293530 A1, Sep. 15, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. H01L 23/544 (2006.01); H01L 21/02 (2006.01); H01L 21/8234 (2006.01); H01L 27/088 (2006.01); H01L 29/66 (2006.01); H01L 29/78 (2006.01)
CPC H01L 23/544 (2013.01) [H01L 21/02389 (2013.01); H01L 21/823431 (2013.01); H01L 27/0886 (2013.01); H01L 29/66795 (2013.01); H01L 29/785 (2013.01); H01L 2223/54426 (2013.01)] 21 Claims
OG exemplary drawing
 
1. A method of forming an alignment mark array, the method comprising:
providing a III-V compound substrate having a device region and an alignment mark region, wherein the III-V compound substrate is characterized by a processing surface;
forming a hardmask layer having a first set of openings on the alignment mark region exposing a first surface portion of the processing surface of the III-V compound substrate and a second set of openings on the device region exposing a second surface portion of the processing surface of the III-V compound substrate, wherein each of the first set of openings corresponds to an alignment mark of the alignment mark array;
etching the first surface portion and the second surface portion of the III-V compound substrate using the hardmask layer as a mask to form a plurality of trenches; and
epitaxially regrowing a semiconductor layer in the trenches to form the alignment marks extending to a predetermined height over the processing surface of the III-V compound substrate.