Patent ID: 7602693

Claim:
A data recording apparatus comprising: a recording medium that includes a semiconductor substrate; a first insulating layer which is formed on a first surface of the semiconductor substrate; a second insulating layer which is formed on the first insulating layer and is made to accumulate electric charge; an electrode layer which is formed on a second surface of the semiconductor substrate; and an insulating area which penetrates the first and the second insulating layers and whose bottom is disposed in the semiconductor substrate; and an electrode that applies a voltage to the recording medium, wherein a depth from an interface between the semiconductor substrate and the first insulating layer to the bottom of the insulating area is more than a maximum depth of a depletion layer, W max which is represented by W max =√{square root over (2∈ 0 ∈ i ×2|φ f |/qN d )} where ∈ 0 is a dielectric constant of vacuum, ∈ i is a relative dielectric constant, |φ f | is an absolute value of the Felmi potential of the semiconductor substrate, q is an electric charge of an electron, and N d is an impurity concentration of the semiconductor substrate.