6-inch GaN wafers have more than twice the usable surface area than 4-inch wafers, resulting in a larger yield of MMICs from each platform. (Image courtesy of ThinkStock).

Qorvo Starts Manufacturing Six-Inch Gallium Nitride Wafers

Sept. 1, 2015
Qorvo recently scaled up its GaN manufacturing process to 6 inches, up from 4 inches. It's the latest attempt to reduce the steep production cost of GaN.

Although gallium nitride (GaN) power amplifiers support a wide range of frequency bandwidths and high breakdown voltages, the manufacturing process remains too costly to exploit these benefits on a large scale. In an attempt to increase its GaN capabilities, Qorvo recently scaled its QGaN25 production process to support monolithic microwave integrated circuits (MMICs) on 6-inch wafers, up from its previous 4-inch substrates.

For Qorvo, the transition is expected to more than double its existing GaN-on-silicon carbide (SiC) manufacturing capabilities, the company said in a recent statement. The 6-inch GaN wafers have more than twice the usable surface area than previous 4-inch wafers, resulting in a larger yield of integrated circuits (ICs) per substrate. This process will also reduce the production cost of its GaN-based technologies, which are used in commercial base receiver stations (BTSs), point-to-point radios, and military radars.

The production process was engineered as GaN technologies are growing more widespread. The market for GaN radio frequency (RF) devices is expected to reach around $560 million in 2019, according to a recent Strategy Analytics report. This can be largely attributed to its steady presence in military-grade radars and increased usage in wireless infrastructure, the report noted. On the other hand, the shift toward small-cell architectures is expected to moderate future growth in the commercial sector, the report concluded.

Qorvo has stated that the latest GaN process is part of a strategy to convert all its GaN-on-SiC production to 6-inch wafers, with gate lengths ranging from 0.15 μm to 0.50 μm. This production process can produce 12-watt X-band MMIC power amplifiers that reach 80% dc and RF yields. Full-rate production of the GaN wafers is anticipated for 2016, according to the company.

Qorvo has previous experience with 6-inch GaN wafers, but it has never produced the wafers on its QGaN25 production process. Before RF Micro Devices (RFMD) and Triquint Semiconductors merged to form Qorvo earlier this year, RFMD had produced 6-inch wafers using an existing gallium-arsenide (GaA) foundry in 2013. At that point, the new process was part of the company’s restructuring plan to convert all of its existing GaA foundries into GaN production.