摘要 |
A semiconductor optical memory includes a gate layer composed of a p- first semiconductor layer, a p- or n- second semiconductor layer, and an n- third semiconductor layer provided between a cathode layer and an anode layer. Where the second layer is of n- type, an impurity concentration of the n- second semiconductor layer is lower than an impurity concentration of the n- third semiconductor layer, and a bandgap eneray of the n- third semiconductor layer is lower than bandgap energies of the cathode and anode layers. Where the second layer is of p- type, an impurity concentration of the p- second semiconductor layer is lower than an impurity concentration of the p- first semiconductor layer, and a bandgap energy of the p- first semiconductor layer is lower than bandgap energies of the cathode and anode layers. As a result, a response speed becomes as fast as several 100 Mb/s.
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