CN106601810A - Semiconductor device manufacturing method - Google Patents

Abstract

The invention provides a FinFET manufacturing method, which adopts one-time or multiple-time oxidation process to process a low-concentration germanium-silicon layer, consumes silicon atoms in the low-concentration germanium-silicon layer, further increases the concentration of the germanium atoms, is favorable for obtaining a device channel with higher mobility, and makes further improvement of FinFET performance possible; meanwhile, the substrate of the invention adopts a bulk silicon substrate, compared with an SOI substrate, the cost can be greatly reduced, and the oxidation process is compatible with the traditional process and can not increase the process difficulty.

Description

Semiconductor device manufacturing method

technical field

The present invention relates to the field of semiconductor device manufacturing methods, in particular to a method for manufacturing FinFET semiconductor devices.

Background technique

In the past 30 years, semiconductor devices have been proportionally reduced in accordance with Moore's law, the feature size of semiconductor integrated circuits has been continuously reduced, and the integration level has been continuously improved. As the technology node enters the deep sub-micron field, such as within 100nm or even within 45nm, the traditional field effect transistor (FET), that is, planar FET, begins to encounter the limitations of various basic physical laws, making its prospect of scaling down challenged . Many new structure FETs have been developed to meet the actual needs, among which, the FinFET integrated with high mobility channel is a new structure device with great potential for scaling down.

The manufacturing method of the high mobility channel FinFET device is usually to grow the high mobility channel material on the silicon substrate. The high-mobility channel is usually made of high-mobility materials, such as germanium, silicon germanium, group III and V materials, and group II and VI materials. After the growth of the high-mobility material is completed, fins (Fin) made of the high-mobility material are formed. A relatively simple integration solution in the prior art is to directly epitaxially epitaxial a layer of silicon germanium on a silicon substrate as a high-mobility material, and then perform patterning to form fins; and then form an STI structure for electrical isolation.

But the conventional integration process faces some problems. When the concentration of high-mobility materials such as germanium is higher, the carrier mobility is higher, but as the concentration of germanium increases, the critical thickness of the epitaxial layer of germanium silicon or germanium (critical thickness, that is, exceeding this thickness will be reduced) More defects) will be reduced; and when there are more defects in the epitaxial layer, the carrier mobility of the channel material will be degraded, which hinders the improvement of device performance. In addition, if the concentration of germanium is increased through thermal oxidation, germanium will diffuse to the substrate during the high temperature process, resulting in the loss of germanium and failing to obtain a device channel with a higher concentration of germanium. In the prior art, an SOI substrate is usually used to solve the diffusion problem, and the buried oxide layer in the substrate will prevent germanium from diffusing into the substrate, but the high cost of the SOI substrate prevents the wider application of this solution.

Therefore, it is necessary to provide a new FinFET manufacturing method to form a high-mobility channel in a simpler and more effective way.

Contents of the invention

The invention proposes a FinFET manufacturing method, which adopts the method of oxidizing the high-mobility material layer to form a high-mobility channel FinFET device in a more convenient and effective way.

The invention provides a method for manufacturing a semiconductor device, which is used to manufacture a FinFET device, comprising the following steps:

provide the substrate;

forming an anti-germanium diffusion barrier layer on the substrate;

forming a low-concentration germanium-silicon layer on the germanium-resistant diffusion barrier layer;

Perform one or more oxidation processes to consume silicon in the low-concentration silicon-germanium layer, thereby increasing the content of germanium in the low-concentration silicon-germanium layer to form a high-concentration silicon-germanium layer.

According to one aspect of the present invention, after performing one or more oxidation processes, the fins including the high-concentration germanium-silicon layer are formed.

According to one aspect of the present invention, the anti-germanium diffusion barrier layer includes carbon element.

According to one aspect of the present invention, the low-concentration germanium-silicon layer is formed by an epitaxial process, and the concentration of germanium is 5%-50%.

According to one aspect of the present invention, the parameters of the oxidation process are: a temperature of 500-1200° C., and an oxidation time of 1 minute to 10 hours.

The advantage of the present invention is that one or more oxidation processes are used to process the low-concentration germanium-silicon layer, consume the silicon atoms therein, and increase the concentration of germanium atoms, which is beneficial to obtain device channels with higher mobility , making it possible to further improve the performance of FinFET; at the same time, because the substrate of the present invention uses a bulk silicon substrate, compared with the SOI substrate, the cost can be greatly reduced, and the oxidation process is compatible with the traditional process, and does not increase the process difficulty.

Description of drawings

1-4 are schematic flow charts of the semiconductor manufacturing method provided by the present invention.

detailed description

Hereinafter, the present invention is described by means of specific embodiments shown in the drawings. It should be understood, however, that these descriptions are exemplary only and are not intended to limit the scope of the present invention. Also, in the following description, descriptions of well-known structures and techniques are omitted to avoid unnecessarily obscuring the concept of the present invention.

The invention provides a method for manufacturing a semiconductor device, and in particular, relates to a method for manufacturing a FinFET device. Hereinafter, referring to the accompanying drawings, the semiconductor device manufacturing method provided by the present invention will be described in detail.

First, referring to FIG. 1 , a substrate 1 is provided, and an anti-germanium diffusion barrier layer 2 is formed on the substrate 1 . In a preferred embodiment of the present invention, the substrate 1 is a bulk silicon substrate, which is beneficial to reduce costs compared with an SOI substrate. The anti-germanium diffusion barrier layer 2 is used to prevent impurity elements in the subsequently formed high-mobility epitaxial layer from diffusing to the substrate and to prevent dopant elements in the substrate 1 from diffusing into the epitaxial layer. Implantation on the substrate 1 or formed in an epitaxial manner. The anti-germanium diffusion barrier layer 2 includes elements with an atomic number smaller than that of germanium, preferably carbon elements for barrier effect, and its thickness is preferably 1-100 nm, preferably 5-20 nm.

Next, referring to FIG. 2 , a low-concentration silicon-germanium layer 3 is formed on the anti-germanium diffusion barrier layer 2 . Wherein, the method of forming the low-concentration germanium-silicon layer 3 is epitaxy. Wherein, "low concentration" refers to the high-mobility germanium-silicon material layer whose germanium concentration is increased through an oxidation process. Preferably, the concentration of germanium in the low-concentration germanium-silicon layer 3 is 5%-50%, preferably 25%-50%. The thickness of the low-concentration germanium-silicon layer 3 is set according to the fin height of the FinFET device to be formed, preferably 10nm-100nm, preferably 30nm-60nm.

Afterwards, referring to FIG. 3 , one or more oxidation processes are performed to consume the silicon in the low-concentration silicon-germanium layer 3, thereby increasing the germanium content in the low-concentration silicon-germanium layer 3 to obtain the high-concentration silicon-germanium layer 4. The concentration of germanium in the silicon germanium layer is 40-80%. The oxidation process is set as follows: the oxidation process atmosphere is a gas containing oxygen elements, preferably oxygen; the oxidation temperature is 500-1200°C, preferably 500-1050°C; the oxidation time is preferably 1 minute-10 hours, preferably 10 minutes- 2 hours. Here, the oxidation process can be selected to perform one or more oxidations as required, and the oxidation time and oxidation temperature are selected according to the above settings. In the oxidation process, the silicon in the low-concentration silicon-germanium layer 3 is oxidized to form silicon oxide, and the silicon in the low-concentration silicon-germanium layer 3 is consumed after one or more oxidation processes. After this process, the germanium concentration in the low-concentration silicon-germanium layer 3 increases, and then becomes the high-concentration silicon-germanium layer 4 .

Next, referring to FIG. 4 , after the high-concentration silicon-germanium layer 4 is obtained, fins including the high-concentration silicon-germanium layer 4 and isolation structures 5 between different fins are formed.

In the above, the semiconductor device manufacturing method of the present invention has been described. In the method of the present invention, one or more oxidation processes are used to process the low-concentration germanium-silicon layer, consume the silicon atoms therein, and increase the concentration of germanium atoms, which is beneficial to obtain device trenches with higher mobility. It makes it possible to further improve the performance of FinFET; at the same time, because the substrate of the present invention uses a bulk silicon substrate, compared with the SOI substrate, the cost can be greatly reduced, and the oxidation process is compatible with the traditional process, and will not increase Craft difficulty.

The method of the present invention can not only be aimed at the silicon germanium material layer, but also can be aimed at other material layers suitable for separating silicon and high-mobility element materials by adopting an oxidation process.

Although the invention has been described with reference to one or more exemplary embodiments, those skilled in the art will recognize various suitable changes and equivalents in device structures and/or process flows without departing from the scope of the invention. In addition, many modifications, possibly suited to a particular situation or material, may be made from the disclosed teaching without departing from the scope of the invention. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode for carrying out this invention, but that the disclosed device structures and methods of making the same will include all embodiments falling within the scope of the invention .

Claims (5)

1. a kind of method, semi-conductor device manufacturing method, for manufacturing FinFET, its feature exists In comprising the steps：

Substrate is provided；

Anti- germanium diffusion impervious layer is formed over the substrate；

Low concentration germanium silicon layer is formed on the anti-germanium diffusion impervious layer；

Once or repeatedly oxidation technology is carried out, the silicon in the low concentration germanium silicon layer is consumed, from And the Ge content in the low concentration germanium silicon layer is improved, form high concentration germanium silicon layer.

2. method according to claim 1, it is characterised in that carry out it is once or many After secondary oxidation technology, formation includes the fin of the high concentration germanium silicon layer.

3. method according to claim 1, it is characterised in that the anti-germanium diffusion barrier Layer includes carbon.

4. method according to claim 1, it is characterised in that the low concentration germanium silicon layer Formed using epitaxy technique, germanium concentration is 5%-50%.

5. method according to claim 1, it is characterised in that the ginseng of the oxidation technology Number is：500～1200 DEG C of temperature, oxidization time is 1 minute～10 hours.