US 11,869,947 B2
Gallium-nitride-based module with enhanced electrical performance and process for making the same
Julio C. Costa, Oak Ridge, NC (US); and Michael Carroll, Jamestown, NC (US)
Assigned to Qorvo US, Inc., Greensboro, NC (US)
Filed by Qorvo US, Inc., Greensboro, NC (US)
Filed on May 3, 2021, as Appl. No. 17/306,194.
Application 17/306,194 is a division of application No. 16/374,125, filed on Apr. 3, 2019.
Claims priority of provisional application 62/652,380, filed on Apr. 4, 2018.
Prior Publication US 2021/0257464 A1, Aug. 19, 2021
Int. Cl. H01L 29/20 (2006.01); H01L 21/02 (2006.01)
CPC H01L 29/2003 (2013.01) [H01L 21/0262 (2013.01); H01L 21/02389 (2013.01); H01L 21/02458 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A method comprising:
providing a precursor package having a plurality of switch dies, a package substrate, and a first mold compound, wherein:
the package substrate includes a plurality of module substrates, wherein an inter-module area is in between two adjacent module substrates of the plurality of module substrates;
each of the plurality of switch dies resides over a corresponding module substrate, and comprises an electrode region, a plurality of switch interconnects extending from a bottom surface of the electrode region to the corresponding module substrate, an aluminium gallium nitride (AlGaN) barrier layer over a top surface of the electrode region, a gallium nitride (GaN) buffer layer over the AlGaN barrier layer, a lateral two-dimensional electron gas (2DEG) layer realized at a heterojunction of the AlGaN barrier layer and the GaN buffer layer, and a silicon switch substrate over the GaN buffer layer; and
the first mold compound encapsulates side surfaces of each of the plurality of switch dies, wherein a top surface of the silicon switch substrate of each of the plurality of switch dies is exposed;
removing substantially the silicon switch substrate of each of the plurality of switch dies to provide a plurality of thinned switch dies and form an opening over each of the plurality of thinned switch dies, wherein a top surface of each of the plurality of thinned switch dies is exposed at a bottom of the opening;
applying a second mold compound to substantially fill each opening to form a GaN based package; and
singulating the GaN based package at each inter-module area to provide a plurality of GaN based modules, wherein each of the plurality of GaN based modules includes one module substrate and at least one thinned switch die.