Direct observation of the depletion layer in a multichannel vertical j.f.e.t. (m.j.f.e.t.)

The letter reports direct observations of the spreading behaviour of the depletion layer into the channel region of the m.j.f.e.t. by scanning electron microscopy. The results are discussed in connection with electrical characteristics. A mechanism for the triode-like operation is also clarified by the concept of a potential profile.