INTEGRATED TRENCH MOSFET AND JUNCTION BARRIER SCHOTTKY RECTIFIER WITH TRENCH CONTACT STRUCTURES

• US 20090315107A1
• Filed: 06/23/2008
• Published: 12/24/2009
• Est. Priority Date: 06/23/2008
• Status: Active Grant

• Current Assignee: Force Mos Technology Co., Ltd.
• Original Assignee: Force Mos Technology Co., Ltd.
• Inventors: Hsieh, Fu-Yuan
• Granted Patent: US 7,626,231 B1
• Time in Patent Office: Days
• US Class Current: 257/334
• CPC Class Codes: H01L 29/0619 with a supplementary region doped oppositely to or in rectifying contact with the semiconductor containing or contacting region, e.g. guard rings with PN or Schottky junction
• CPC Class Codes: H01L 29/0623 Buried supplementary region, e.g. buried guard ring multi-RESURF H01L29/0634
• CPC Class Codes: H01L 29/0878 Impurity concentration or distribution
• CPC Class Codes: H01L 29/41766 with at least part of the source or drain electrode having contact below the semiconductor surface, e.g. the source or drain electrode formed at least partially in a groove or with inclusions of conductor inside the semiconductor H01L29/41733 - H01L29/41758 take precedence
• CPC Class Codes: H01L 29/42368 the thickness being non-uniform
• CPC Class Codes: H01L 29/456 on silicon
• CPC Class Codes: H01L 29/47 Schottky barrier electrodes H01L29/435 takes precedence
• CPC Class Codes: H01L 29/66143 Schottky diodes
• CPC Class Codes: H01L 29/66727 with a step of recessing the source electrode
• CPC Class Codes: H01L 29/66734 with a step of recessing the gate electrode, e.g. to form a trench gate electrode
• CPC Class Codes: H01L 29/7803 structurally associated with at least one other device assemblies H01L25/00; integrated circuits H01L27/00
• CPC Class Codes: H01L 29/7813 with trench gate electrode, e.g. UMOS transistors trench gate electrodes per se H01L29/4236
• CPC Class Codes: H01L 29/861 Diodes
• CPC Class Codes: H01L 29/872 Schottky diodes

Abstract

A trench MOSFET in parallel with trench junction barrier Schottky rectifier with trench contact structures is formed in single chip. The present invention solves the drawback brought by some prior arts, for example, the large area occupied by planar contact structure and high gate-source capacitance. As the electronic devices become more miniaturized, the trench contact structures of this invention are able to be shrunk to achieve low specific on-resistance of Trench MOSFET, and low Vf and reverse leakage current of the Schottky Rectifier.

Claims

1. An Integrated Circuit having a plurality of trench MOSFET and a plurality of Junction Barrier Schottky rectifier comprising:

a substrate of the first conductivity type;

an epitaxial layer of said first conductivity type over said substrate, said epitaxial layer having a lower doping than said substrate;

a trenched MOSFET comprising a trenched gate surrounded by a source region encompassed in a body region above a drain region disposed on a bottom surface of a substrate, wherein said trench MOSFET further comprising;

an insulation layer covering said integrity circuit with a source-body contact trench opened there through said source and extended into body regions and filled with contact metal plug therein, wherein a gate oxide lining said trench gate and a doped polysilicon within said trenches and overlying the gate oxide. and

a junction barrier Schottky rectifier extending into said epitaxial layer and having a barrier layer lined in trench contact filled with contact metal plug and between a pair of adjacent P-bodies.

3. The gate oxide in claim 1 is single gate oxide or double gate oxides with thicker gate oxide on trench bottom.

4. The barrier layer lines said contact trench in claim 1 is Ti/TiN or Co/TiN.

5. The contact metal plug overlying the barrier layers in claim 4 is Tungsten.

6. The Schottky barrier in claim 1 comprises TiSi2 (Ti Silicide) or CoSi2 (Co Silicide).

7. The Schottky barrier in claim 6 lines along contact trench sidewall and bottom, or only sidewall.

2. The epitaxial layer is single or double epitaxial layers with doping concentration of top epitaxial layer less than bottom epitaxial layer.

8. The source/anode metal is Aluminum alloys or Copper on top of Ti or Ti/TiN layer.