CN-224218741-U - Electronic device

Abstract

The present disclosure relates to electronic devices. An electronic device comprising a body of semiconductor material having a surface and an N-type conductivity, a switching region of P-type conductivity extending into the body from the surface, and an ohmic contact region at the switching region, wherein further comprising a surface portion of P-type conductivity extending at least between the switching regions at the surface of the body, and a metal layer over the surface of the body, the metal layer being in electrical contact with the body through the surface portion and with the switching region through the ohmic contact region.

Inventors

• S. Rescuna
• G. Beloch
• F. Roca Ford

Assignees

• 意法半导体国际公司

Dates

Publication Date

20260508

Application Date

20250221

Priority Date

20240223

Claims (10)

1. 1. An electronic device, the electronic device comprising: a body of semiconductor material having a surface and N-type conductivity; A switching region of P-type conductivity extending from said surface into said body, and An ohmic contact region at the switching region, Wherein the electronic device further comprises: A surface portion having a P-type conductivity, the surface portion extending at least between the switching regions at the surface of the body, and A metal layer over the surface of the body, the metal layer being in electrical contact with the body through the surface portion and with the switching region through the ohmic contact region.
2. 2. The electronic device of claim 1, wherein the surface portion extends along the entire surface in an electrically continuous manner.
3. 3. The electronic device of claim 1, wherein the surface portion is in direct electrical contact with the switching region.
4. 4. The electronic device of claim 1, wherein the contact metal layer is in direct electrical contact with the surface portion.
5. 5. The electronic device of claim 1, wherein the metal layer is made of a metal for forming a schottky contact with the surface portion, a barrier height of the schottky contact being comprised between 0.7 and 1.2 eV.
6. 6. The electronic device of claim 5, wherein the metal layer is made of a metal for forming a schottky contact with the surface portion, the schottky contact having a barrier height equal to 0.9 eV.
7. 7. The electronic device of claim 1, wherein the contact metal layer is one of TiN, mo, moN, WN, WC, ta or TaN.
8. 8. The electronic device of claim 1, wherein the body is made of silicon carbide SiC.
9. 9. The electronic device of claim 1, wherein the body comprises an epitaxial layer on a substrate, the surface belongs to the epitaxial layer, and the surface portion has a depth in the epitaxial layer from the surface that is less than a depth of the switching region.
10. 10. The electronic device of claim 1, wherein the electronic device forms a junction barrier schottky JBS diode or a merged PiN schottky MPS diode.

Description

Electronic device Cross Reference to Related Applications The present application claims the benefit of priority from italian patent application No. 102024000003835, entitled "METODO PER LA REGOLAZIONE DELL'ALTEZZA DELLA BARRIERA SCHOTTKY IN UN DIODO DIPOTENZA IN CARBURO DI SILICIO,E DIODO DIPOTENZA", filed 2/23 at 2024, which is hereby incorporated by reference to the maximum extent allowed by law. Technical Field The present disclosure relates to electronic devices and processes for making the same, and in particular to a method for adjusting the schottky barrier height in silicon carbide power diodes and power diodes thereof. Background Electronic devices known as JBS (junction barrier Schottky (Junction Barrier Schottky)) or MPS (merged PiN Schottky (MERGED PIN Schottky)) diodes are known. Such devices are typically fabricated in silicon carbide (SiC) substrates and include an implanted region (e.g., P-type for N-type substrates) having a conductivity opposite that of the substrate. In these devices, there are two different types of contacts, an ohmic contact at the implanted regions and a schottky contact contained in the region between the implanted regions. These features make JBS diodes particularly suitable for operation in high voltage power devices. Today, minimizing conduction losses in discrete power devices is a critical requirement to reduce the total energy consumption of modern power circuits and modules. For this reason, the possibility to control the Schottky Barrier Height (SBH) value is a very important aspect of adjusting the voltage drop of the schottky diode. Reducing SBH results in a significant reduction in pressure drop. As a negative effect, decreasing SBH results in a substantial increase in leakage current in reverse mode. Therefore, there is a need for a JBS diode with high efficiency under forward bias without the disadvantages of high loss in reverse mode or reverse bias. Disclosure of Invention It is an object of the present disclosure to provide a device and a method of manufacturing the same that overcomes the shortcomings of the prior art and meets the needs described above. According to the present disclosure, there is provided an electronic device and a process for manufacturing the same, as claimed in the appended claims. According to an aspect of the present disclosure there is provided an electronic device comprising a body of semiconductor material having a surface and an N-type conductivity, a switching region of P-type conductivity extending into the body from the surface, and an ohmic contact region at the switching region, wherein there is further provided a surface portion of P-type conductivity extending at least between the switching regions at the surface of the body, and a metal layer over the surface of the body, the metal layer being in electrical contact with the body through the surface portion and with the switching region through the ohmic contact region. According to some embodiments of the disclosure, the surface portion extends along the entire surface in an electrically continuous manner. According to some embodiments of the disclosure, the surface portion is in direct electrical contact with the switching region. According to some embodiments of the disclosure, the contact metal layer is in direct electrical contact with the surface portion. According to some embodiments of the disclosure, wherein the metal layer is made of a metal for forming a schottky contact with the surface portion, the barrier height of the schottky contact is comprised between 0.7 and 1.2eV, in particular equal to 0.9eV. According to some embodiments of the disclosure, wherein the contact metal layer is one of TiN, mo, moN, WN, WC, ta or TaN. According to some embodiments of the disclosure, wherein the body is made of silicon carbide SiC. According to some embodiments of the disclosure, wherein the body comprises an epitaxial layer on a substrate, the surface belongs to the epitaxial layer, the surface portion has a depth in the epitaxial layer from the surface that is less than a depth of the switching region. According to some embodiments of the disclosure, wherein the surface portion has a P-type doping value comprised between 10 11 and 10 14at/cm3. According to some embodiments of the present disclosure, a junction barrier schottky JBS diode or a merged PiN schottky MPS diode is formed. According to another aspect of the present disclosure there is provided a method of manufacturing an electronic device comprising forming, in a solid body of semiconductor material having a surface and an N-type conductivity, a switching region having a P-type conductivity, the switching region extending into the body from the surface and being defined between regions of the surface of the solid body, forming a surface layer having a P-type conductivity, the surface layer extending at the surface at least between the switching regions, forming an ohmic contact region at the switching r