## Abstract

We demonstrate the characteristics of p^{+}-Ge/n-Si and n ^{+}-Ge/p-Si heterojunction diodes with a very high on/off ratio and very low leakage current using heteroepitaxial Ge grown directly on Si. The current ratio of p^{+}-Ge/n-Si and n^{+}-Ge/p-Si heterojunction is ∼5 × 10^{7} and ∼3 × 10^{6}, respectively. The remarkably low off current density is 2.1 μA/cm^{2} for p^{+}-Ge/n-Si and 19 μA/cm^{2} for n^{+}-Ge/p-Si at a reverse bias of |V_{F}| = ±1 V, respectively. High on current density (125 A/cm^{2} for p^{+}-Ge/n-Si and 54 A/cm ^{2} for n^{+}-Ge/p-Si) with a forward bias |V_{F}| = ±1 V is obtained with a GeO_{2} passivation and an Al _{2}O_{3} isolation.

Original language | English |
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Article number | 024001 |

Journal | Applied Physics Express |

Volume | 6 |

Issue number | 2 |

DOIs | |

State | Published - 1 Feb 2013 |