This application claims the benefits of Taiwan application Serial No. 109122350, filed on Jul. 2, 2020, the disclosures of which are incorporated by references herein in its entirety.
The present invention relates to an etching protection layer of metal semiconductor junction, in particular to an etching protection layer structure of metal semiconductor junction and manufacturing method thereof.
A highly doped contact layer of the metal semiconductor junction is susceptible to physical and chemical damage due to the cleaning or etching process of high-power plasma during the production process of each process station. This increases the density of surface defects or severely damages the surface of the contact layer, thereby changing the photoelectric characteristics of the device, and even electrical effects that cannot be remedied by the high temperature annealing process.
Materials such as titanium nitride (TiN), silicon nitride (SiN), and silicon dioxide (SiO2) commonly used as hard masks for the ridge structure of a laser device in the inductively coupled plasma reactive ion etching (ICP-RIE) process must be removed at the end of the process.
The present invention uses titanium (Ti)/platinum (Pt) as the etching protection layer (ridge metal) of the semiconductor contact layer above the ridge waveguide of the laser device to avoid damage to the surface caused by the high-power plasma during the manufacturing process, so as to ensure that the photoelectric characteristics of the device are not affected and reduce the reliability risk.
An objective of the present invention is to provide an etching protection layer structure of metal semiconductor junction and manufacturing method thereof. The metal etching protection layer can serve as an etching mask for a ridge structure of laser device during an inductively coupled plasma reactive ion etching (ICP-RIE) process.
The present invention achieves the above-indicated objective by providing an etching protection layer structure of metal semiconductor junction including a semiconductor substrate and a metal etching protection layer. The semiconductor substrate has a metal semiconductor contact layer. The metal etching protection layer is disposed on the metal semiconductor contact layer, and serves as an etching mask for the ridge structure of laser device during the inductively coupled plasma reactive ion etching (ICP-RIE) process. The metal etching protection layer is not necessary to remove after completing the ICP-RIE process.
Compared to a conventional hard mask, the present invention has several advantages:
1. The metal etching protection layer of the present invention can serve as an etching mask for a ridge structure of laser device during an inductively coupled plasma reactive ion etching (ICP-RIE) process, and the metal etching protection layer is not necessary to remove after completing the ICP-RIE process.
2. The metal etching protection layer (ridge metal) not only protects the semiconductor contact layer from high-power plasma resulting in surface damage and defects, and it can replace the materials commonly used as hard masks for etching, such as dielectric materials TiN, SiN, SiO2. The metal etching protection layer (ridge metal) can meet the same protecting function as the dielectric material etching mask, and can be used in the ICP-RIE dry etching process to make laser ridge waveguides to achieve the dual-use effect of the protection layer and the etching mask. After the dry etching process is completed, there is no need to remove the ridge metal, but the aforementioned dielectric material etching mask must be removed at the end of the process.
The etching protection layer of the present invention serves as an etching mask for a ridge structure of laser device during an inductively coupled plasma reactive ion etching (ICP-RIE) process, and the metal etching protection layer is not necessary to remove after completing the ICP-RIE process.
A metal etching protection layer 42 is disposed on the metal semiconductor contact layer 22, and serves as an etching mask for a ridge structure 20 of laser device during an inductively coupled plasma reactive ion etching (ICP-RIE) process. The metal etching protection layer 42 is not necessary to remove after completing the ICP-RIE process. The metal etching protection layer 42 is a P-type metal of platinum (Pt), titanium (Ti)/platinum (Pt), or titanium (Ti)/platinum (Pt)/gold (Au). The present invention uses titanium (Ti)/platinum (Pt) as an etching protection layer (ridge metal) of the metal semiconductor contact layer 22 above the ridge structure 20 (waveguide).
Next, a photolithography process is used to define a pattern of metal etching protection layer 32 on the semiconductor substrate 10. A pretreatment process of this photolithography process is to first remove the surface oxide layer of the semiconductor substrate 10. And, a photoresist 30 is coated on the semiconductor substrate 10. A photomask is used to expose on the photoresist 30 to define the pattern of metal etching protection layer 32. Then, the photoresist 30 is developed to form the pattern of the protection layer pattern 32, as shown in
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Number | Date | Country | Kind |
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109122350 | Jul 2020 | TW | national |