For an n-type GaAs MESFET, the work function difference in the gate junction is:<br /> <br /> a. qΦm>qΦs<br /> b. qΦmΦs<br /> c. qΦm=qΦs<br /> d. other<br /> A、a. qΦm>qΦs<br /> B、b. qΦm<qΦs<br /> C、c. qΦm=qΦs<br /> D、d. other