Patent ID: 8390081
Filing Date: 2013-03-05
Classification: H01L

Abstract:
1. A MOS P-N junction diode device, comprising: a n type substrate; a field oxide structure formed on the n type substrate and defining a trench structure; a gate structure formed in the trench structure; a single p type Boron ion doped region formed in the n type substrate and adjacent to the gate structure, and comprising a plurality of adjacent p type Boron ion doped sub-regions with different implantation depths, the adjacent p type Boron ion doped sub-regions extending from a surface of the n type substrate; a p type guard ring in the n type substrate adjacent to the field oxide structure and the single p type Boron ion doped region, wherein the single p type Boron ion doped region comprises a first p type Boron ion doped sub-region shallower than the p type guard ring and a second p type Boron ion doped sub-region shallower than the first p type Boron ion doped sub-region, the second p type Boron ion doped sub-region disposed between the gate structure and the first p type Boron ion doped sub-region; and a top electrode and a bottom electrode formed on opposite surfaces of the n type substrate wherein the top electrode is disposed on the trench structure and the field oxide structure and a portion of the field oxide structure is exposed from the top electrode, and an ohmic contact being formed between the top electrode and the single p type Boron ion doped region; wherein the top electrode includes a titanium nitride contacted to the single p type Boron ion doped region and an aluminum covered on the titanium nitride, and the titanium nitride is subjected to a rapid thermal nitridation.