Power semiconductor component for high reverse voltages

Details Power semiconductor component for high reverse voltages Power semiconductor component for high reverse voltages

2001-01-17

2002-08-27

Jackson, Jr., Jerome (Department: 2815)

Active solid-state devices (e.g., transistors, solid-state diode

Regenerative type switching device

Combined with field effect transistor

C257S139000, C257S147000, C257S341000, C257S103000, C257S104000

Reexamination Certificate

active

06441408

ABSTRACT:

BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to power semiconductor components, in particular for high reverse voltages. The power semiconductor components include an n-doped silicon layer, into which a plurality of n- or p-doped layers are introduced between a first main area and a second main area. A cathode is assigned to the first main area and is formed by a first metallization layer. An anode, which is formed by a second metallization layer, covers the second main area.
Such power semiconductor components can be constructed in such a way that the layers, as seen from the second main area, include a p-doped anode zone, an n-doped stop layer which has a higher dopant concentration than a silicon layer which adjoins the stop layer.
Such components are widely known as bipolar transistors, thyristors or as field effect-controllable bipolar power semiconductor components, such as insulated gate bipolar transistors and are presented in U.S. Pat. No. 5,668,385 for example.
In another embodiment, the above-mentioned power semiconductor components can have layers which, as seen from the second main area, include a p-doped anode zone and, adjoining the latter, the n-doped silicon layer, adjoining that a stop layer, which has a higher dopant concentration than the n-doped silicon layer, and adjoining the stop layer an n-doped cathode zone.
Such power semiconductor components are generally known as diodes, and may either be present as discrete actual components or be contained as parasitic diodes in other power semiconductor components such as e.g. in power MISFETs (Metal-Insulator-Semiconductor Field-Effect Transistors). In a power MISFET, as is known, a parasitic p
+
-n
−
-n
+
diode is reverse-connected in parallel with the actual MISFET from the source to the drain. Such power semiconductor components are likewise presented in U.S. Pat. No. 5,668,385 for example.
Such stop layers have hitherto been fabricated predominantly by deep diffusions which, however, require very long diffusion times. Furthermore, the doping profile also cannot be freely chosen as is disclosed in Published European Patent Application EP 0 214 485 A1.
Moreover, it is also known to deposit such stop layers epitaxially on a heavily n-doped substrate. However, epitaxy is a very expensive method, in particular with regard to the layer thicknesses required in power semiconductor components, and, in addition, has the problem that undesired, excessively high defect densities are quite often produced.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a power semiconductor component which overcomes the abovementioned disadvantages of the heretofore-known components of this general type and which has a stop layer that does not have to be deposited epitaxially and which can be fabricated without necessitating lengthy deep diffusions.
With the foregoing and other objects in view there is provided, in accordance with the invention, a power semiconductor component, in particular for high reverse voltages, including:
an n-doped silicon layer;
a first main area and a second main area;
a plurality of doped layers introduced into the n-doped silicon layer between the first main area and the second main area;
the doped layers, as seen from the second main area, including a p-doped anode zone and an n-doped stop layer adjoining the p-doped anode zone;
the n-doped silicon layer having a first dopant concentration, the n-doped stop layer having a second dopant concentration higher than the first dopant concentration, the n-doped stop layer adjoining and completely covering the n-doped silicon layer;
the n-doped stop layer being doped with at least one dopant having at least one donor level between a valence band edge of silicon and a conduction band edge of silicon and the at least one donor level being more than 200 meV away from the conduction band edge of silicon;
a cathode assigned to the first main area and formed by a first metallization layer; and
an anode formed by a second metallization layer covering the second main area.
With the objects of the invention in view there is also provided, a power semiconductor component, in particular for high reverse voltages, including:
an n-doped silicon layer;
a first main area and a second main area;
a plurality of doped layers introduced into the n-doped silicon layer between the first main area and the second main area;
the doped layers, as seen from the second main area, including an anode zone, the n-doped silicon layer adjoining the anode zone, a stop layer adjoining the n-doped silicon layer, and an n-doped cathode zone adjoining the stop layer;
the n-doped silicon layer having a first dopant concentration, the stop layer having a second dopant concentration higher than the first dopant concentration, the stop layer completely covering the n-doped silicon layer;
the stop layer being doped with at least one dopant having at least one donor level between a valence band edge of silicon and a conduction band edge of silicon and the at least one donor level being more than 200 meV away from the conduction band edge of silicon;
a cathode assigned to the first main area and formed by a first metallization layer; and
an anode formed by a second metallization layer covering the second main area.
With the objects of the invention in view there is also provided, a semiconductor component, including:
a MISFET having a source, a drain, and a parasitic diode;
the parasitic diode being reverse-connected in parallel from the source to the drain and the parasitic diode including:
an n-doped silicon layer;
a first main area and a second main area;
a plurality of doped layers introduced into the n-doped silicon layer between the first main area and the second main area;
the doped layers, as seen from the second main area, including an anode zone, the n-doped silicon layer adjoining the anode zone, and a stop layer adjoining the n-doped silicon layer;
the n-doped silicon layer having a first dopant concentration, the stop layer having a second dopant concentration higher than the first dopant concentration, the stop layer completely covering the n-doped silicon layer;
the stop layer being doped with at least one dopant having at least one donor level between a valence band edge of silicon and a conduction band edge of silicon and the at least one donor level being more than 200 meV away from the conduction band edge of silicon;
a cathode assigned to the first main area and formed by a first metallization layer; and
an anode formed by a second metallization layer covering the second main area.
According to another feature of the invention, the at least one dopant includes selenium and/or sulfur.
According to another feature of the invention, the n-doped stop layer has a depth of between 1 &mgr;m and 50 &mgr;m.
According to yet another feature of the invention, the p-doped anode zone is embodied as a transparent emitter with a given depth and a given dopant concentration selected such that at least 50% of a total current flowing through the transparent emitter is carried by electrons. The given depth of the transparent emitter is preferably between 0.5 &mgr;m and 5 &mgr;m.
According to another feature of the invention, a plurality of IGBT (Insulated Gate Bipolar Transistor) cells including p-doped base zones and n-doped source zones are introduced from the first main area. The cathode is electrically conductively connected to the p-doped base zones and the n-doped source zones. A gate electrode is provided above the first main area and between respective two of the IGBT cells. An insulator insulating the gate electrode is also provided.
According to another feature of the invention, a p-doped base introduced from the first main area is provided. A plurality of n-doped cathode zones is introduced into the p-doped base, and the n-doped cathode zones are electrically conductively connected to the cathode.
According to another feature of the invention, a plurality of MCT (MOS-controlled thyristor) structures each including a p-

Affiliated with

Also associated with

Rating

Power semiconductor component for high reverse voltages does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Power semiconductor component for high reverse voltages, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Power semiconductor component for high reverse voltages will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2892961