US 2004/0169233 A1Published application

Semiconductor device with surge protection circuit

AssigneeRenesas Technology Corp.

InventorsFumitoshi Yamamoto, Akio Uenishi

Life of this patent

Estimating the term…

Loading patent…

Abstract

A semiconductor device has a surge protection circuit electrically connected to a signal input terminal and including a diode and a transistor. The diode has its cathode region constituted of an n+ diffusion layer, an n− epitaxial layer, an n-type diffusion layer and an n+ diffusion layer. The n+ diffusion layer is electrically connected to a conductive layer and formed at a main surface of a semiconductor substrate. The n+ diffusion layer constitutes, together with a p-type diffusion layer, a pn junction where Zener breakdown occurs, and the pn junction with the Zener breakdown occurring therein is distant from a field oxide film. Then, the semiconductor device with the surge protection circuit without suffering from current leakage and thus normally operating can be achieved.

Claims9

Dependent claims

A semiconductor device including a surge protection circuit electrically connected to a signal input terminal and having a diode and a transistor, comprising:

a semiconductor substrate having a main surface;
a field oxide film formed at the main surface of said semiconductor substrate;
and
a first conductive layer formed on the main surface of said semiconductor substrate and electrically connected to said signal input terminal,
said diode having its cathode including a first cathode region and a second cathode region, said first cathode region being electrically connected to said first conductive layer and formed at the main surface of said semiconductor substrate, and said second cathode region constituting, together with an anode region of said diode, a pn junction where Zener breakdown occurs, and
said pn junction where the Zener breakdown occurs being distant from said field oxide film.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/787,223Filed 27 Feb 2004
Priority: JP 2003-052780(P)28 Feb 2003
Published: 2 Sep 2004
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

H10D 89/811
For devices having insulated gate electrodes, e.g. for IGFETs or IGBTs: using FETs as protective elements
H10D 84/121
Integrated devices comprising main components and built-in components, e.g. IGBT having built-in freewheel diode: bJTs having built-in components
H10D 89/611
For devices having insulated gate electrodes, e.g. for IGFETs or IGBTs: using diodes as protective elements
H10D
Inorganic electric semiconductor devices