A radio frequency power device for implementing asymmetric self-alignment of the source, drain and gate and the production method thereof

Patent metadata

Field	Value
Publication number	US-2016013304-A1
Application number	US-201414651992-A
Country	US
Kind code	A1
Filing date	Mar 25, 2014
Priority date	Mar 25, 2013
Publication date	Jan 14, 2016
Grant date	—

Abstract

The present disclosure relates to the technical field of radio frequency power devices, and more specifically, to a radio frequency power device for implementing the self-position alignment of asymmetric source, drain and gate and the production method thereof. In the radio frequency power device for implementing asymmetric self-alignment of the source, drain and gate according to the present disclosure, gate sidewalls are utilized to implement the self-position alignment of the source, drain and gate, thereby reducing parameter drift of products; besides, the source and drain of the device can be formed by the alloying process, the iron implanting process or epitaxy process after formation of the gate since the gate is protected by the passivating layer, featuring a simple technological process while reducing the parasitic source-drain resistances and enhancing the electrical properties of the radio is frequency power device.

First claim

What is claimed is:

1 . A radio frequency power device for implementing asymmetric self-alignment of the source, drain and gate, comprising:
an AlGaN buffer layer, a GaN channel layer and an AlGaN isolating layer formed in turn on the substrate; a gate dielectric layer formed on the AlGaN isolating layer; wherein, said device also comprises: a gate stack region formed on the gate dielectric layer, including a gate and a passivating layer on the gate; a first gate sidewall formed on either side of the gate stack region; a drain and a source formed respectively on the outer side of the first gate sidewalls on both sides of the gate stack region; a second gate sidewall formed between the first gate sidewall close to one side of the drain and the drain.

2 . The radio frequency power device for implementing asymmetric self-alignment of the source, drain and gate as claimed in claim 1 , wherein a field plate is formed on the first gate sidewall close to the drain, wherein the field plate is connected with the source and extends over the second gate sidewall and the passivating layer on the gate along the length of the current channel of the device.

3 . The radio frequency power device for implementing asymmetric self-alignment of the source, drain and gate as claimed in claim 1 , wherein the source and the drain are located on the AlGaN isolating layer and formed by alloy materials.

4 . The radio frequency power device for implementing asymmetric self-alignment of the source, drain and gate as claimed in claim 1 , wherein the source and the drain are located in the AlGaN isolating layer and formed by the silicon iron doped region in the AlGaN isolating layer.

5 . The radio frequency power device for implementing asymmetric self-alignment of the source, drain and gate as claimed in claim 1 , wherein the source and the drain are located on the GaN channel layer and formed by silicon doped GaN or AlGaN materials.

6 . A production method of the radio frequency power device for implementing asymmetric self-alignment of the source, drain and gate as claimed in claim 1 , wherein the specific steps are as follows:
deposit an AlGaN buffer layer, a GaN channel layer and an AlGaN isolating layer in turn on the substrate; etch the AlGaN isolating layer, the GaN channel layer and the AlGaN buffer layer in turn to form an active region with a photo-resist as the etching stop layer, followed by removal of the resist; deposit the first layer of insulating film, the first layer of conductive film and the second layer of insulating film in turn on the exposed surface of the structure formed; define the location of the gate stack region of the device by photo-etching and development; etch away the second layer of insulating film and the first layer of conductive film exposed in turn with a photo-resist as the etching stop layer, followed by removal of the resist, in this way the remaining first layer of conductive film and second layer of insulating film form the gate stack region which comprises the gate of the device and the passivating layer on the gate; deposit the third layer of insulating film on the exposed surface of the structure formed, and etch the third layer of insulating film to form a first gate sidewall on either side of the gate stack region; deposit a layer of polysilicon on the exposed surface of the structure formed, etch back the polysilicon formed, but only the polysilicon at the source is not etched away; deposit the fourth layer of insulating film on the exposed surface of the structure formed, and etch the fourth layer of insulating film to form the second gate sidewall on the side of the gate stack region close to the drain; etch away the remaining polysilicon, and continue to etch away the first layer of insulating film exposed.

7 . The production method of the radio frequency power device for implementing asymmetric self-alignment of the source, drain and gate as claimed in claim 6 , wherein, also including:
form a pattern by photo-etching to define the locations of the source and the drain respectively; form the source and drain of the device by the lift-off process and the alloying process; form a field plate on the first gate sidewall close to the drain, wherein the field plate is connected with the source and extends over the second gate sidewall and the passivating layer on the gate along the length of the current channel of the device.

8 . The production method of the radio frequency power device for implementing asymmetric self-alignment of the source, drain and gate as claimed in claim 6 , wherein, also including:
form a pattern by the photo-etching process and expose the locations of the source and the drain by means of a pattern; implant silicon irons into the AlGaN isolating layer by the iron implanting process to form the source and drain of the device; form a field plate on the first gate sidewall close to the drain, wherein the field plate is connected with the source and extends over the second gate sidewall and the passivating layer on the gate along the length of the current channel of the device.

9 . The production method of the radio frequency power device for implementing asymmetric self-alignment of the source, drain and gate as claimed in claim 6 , wherein, also including:
continue to etch away the exposed AlGaN isolating layer to expose the GaN channel layer formed; form a pattern by the photo-etching process and expose the locations of the source and the drain by means of a pattern; grow silicon doped GaN or AlGaN by the epitaxy process to form the source and the drain of the device on the exposed GaN channel layer; form a field plate on the first gate sidewall close to the drain, wherein the field plate is connected with the source and extends over the second gate sidewall and the passivating layer on the gate along the length of the current channel of the device.

10 . The production method of the radio frequency power device for implementing asymmetric self-alignment of the source, drain and gate as claimed in claim 6 , wherein the first layer of insulating film is any one of silicon oxide, silicon nitride, hafnium oxide or Al 2 O 3 , while the second layer of insulating film, the third layer of insulating film and the fourth layer of insulating film are any one of silicon oxide or silicon nitride.

11 . The production method of the radio frequency power device for implementing asymmetric self-alignment of the source, drain and gate as claimed in claim 6 , wherein the first layer of conductive film is chromium, nickel or tungsten-containing alloy.

Assignees

• Univ Fudan

Inventors

• Wang Pengfei
• Liu Xiaoyong
• Zhang Wei
• Sun Qingqing
• Zhou Peng

Classifications

• H10D64/0116

  to Group III-V semiconductors · CPC title

• H10P50/692

  characterised by their composition, e.g. multilayer masks or materials · CPC title

• H10P50/646

  of Group III-V materials · CPC title

• H10P50/264

  by chemical means · CPC title

• H10P14/69433

  the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz · CPC title