Method for making semiconductor device using a stress memorization technique

A method for fabricating a semiconductor device is disclosed. A substrate having thereon at least one metal-oxide-semiconductor (MOS) transistor is provided. A stress memorization technique (SMT) process is performed. The SMT process includes steps of depositing an SMT film covering the at least one MOS transistor on the substrate, and subjecting the SMT film to a thermal process. A lithographic process and an etching process are performed to form a patterned SMT film. A silicide layer is formed on the MOS transistor. The patterned SMT film acts as a salicide block layer when forming the silicide layer.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the field of semiconductor technology, in particular to a stress memorization technology (SMT) process.

2. Description of the Prior Art

It is known that stress memorization technology (SMT) is usually performed after the source/drain (S/D) ion implantation step in the semiconductor process to induce stress on the channel area of a metal-oxide-semiconductor field effect transistor (MOSFET).

In the conventional SMT process, a stress layer and laser annealing are usually used to induce stress in the substrate, that is, the polysilicon gate under the stress layer is recrystallized by laser annealing to improve the electrical properties of the N-channel MOSFET (NMOSFET, hereinafter referred to as NMOS). The aforementioned stress layer is removed before the subsequent self-aligned silicidation process.

During the self-aligned metal silicide process, it is necessary to deposit a salicide block (SAB) layer, such as a silicon oxide layer and a silicon nitride layer. Exposure and development processes are performed to pattern the SAB layer to mask the area where the silicide layer is not needed (non-silicide region). However, the above-mentioned SMT process and self-aligned metal silicide process require multiple depositions and etchings, and the steps are relatively complicated.

SUMMARY OF THE INVENTION

It is one object of the present invention to provide an improved manufacturing method of a semiconductor device to solve the above-mentioned deficiencies or shortcomings of the prior art.

One aspect of the invention provides a method for fabricating a semiconductor device. A substrate having thereon at least one metal-oxide-semiconductor (MOS) transistor is provided. A stress memorization technique (SMT) process is performed. An SMT film covering the at least one MOS transistor is deposited on the substrate. The SMT film is then subjected to a thermal process. After the SMT process, a lithographic process and an etching process are performed to form a patterned SMT film. A silicide layer is then formed on the MOS transistor. The patterned SMT film acts as a salicide block layer when forming the silicide layer.

According to some embodiments, the at least one MOS transistor is an NMOS transistor.

According to some embodiments, the SMT film comprises a silicon oxide layer and a silicon nitride layer.

According to some embodiments, the silicon nitride layer is a stressed silicon nitride layer.

According to some embodiments, the patterned SMT film covers a non-silicide region on the substrate that does not need to form a silicide layer.

According to some embodiments, the thermal process comprises a rapid thermal process.

According to some embodiments, the thermal process comprises a laser annealing process.

One advantage of the present invention is that the patterned SMT film is used as a self-aligned silicide block layer when forming the silicide layers. Therefore, the SMT film removal step, the subsequent cleaning step, and the additional steps of depositing and patterning of a self-alignment silicide block layer can be omitted. The present invention can effectively reduce the complexity and manufacturing cost of the steps of manufacturing the semiconductor device.

DETAILED DESCRIPTION

In the following detailed description of the disclosure, reference is made to the accompanying drawings, which form a part hereof, and in which is shown, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention.

Other embodiments may be utilized, and structural, logical, and electrical changes may be made without departing from the scope of the present invention. Therefore, the following detailed description is not to be considered as limiting, but the embodiments included herein are defined by the scope of the accompanying claims.

Please refer toFIG.1toFIG.4, which are schematic diagrams of a method for manufacturing a semiconductor device1according to an embodiment of the present invention. First, as shown inFIG.1, a substrate SB such as a semiconductor substrate is provided. The substrate SB includes a first device region10, a second device region20, and an isolation region30interposed between the first device region10and the second device region20. A first semiconductor device100is formed in the first device region10on the substrate SB, and a second semiconductor device200is formed in the second device region20.

According to an embodiment of the present invention, a trench isolation structure ST located in the isolation region30can electrically isolate the first semiconductor device100from the second semiconductor device200.

According to an embodiment of the present invention, for example, the first semiconductor device100and the second semiconductor device200are metal oxide semiconductor (MOS) transistors. According to an embodiment of the present invention, for example, the first semiconductor device100is an NMOS transistor, and the second semiconductor device200is a PMOS transistor.

According to an embodiment of the present invention, for example, the first semiconductor device100may include a gate110, a source122, and a drain124. A channel130is disposed between the source122and the drain124. According to an embodiment of the present invention, for example, the second semiconductor device200may include a gate210, a source222, and a drain224. A channel230is disposed between the source222and the drain224. According to embodiments of the present invention, for example, the gates110and210may be polysilicon gates.

In addition, according to an embodiment of the present invention, a SiGe epitaxial layer E may be included in the source222and the drain224.

Next, a stress memorization technology (SMT) process is performed, including depositing an SMT film410covering the first semiconductor device100and the second semiconductor device200on the substrate SB. According to an embodiment of the present invention, the SMT film410includes a silicon oxide layer411and a silicon nitride layer412. According to an embodiment of the present invention, the silicon nitride layer412is a stressed silicon nitride layer.

As shown inFIG.2, the SMT film410is next subjected to thermal treatment50. According to an embodiment of the present invention, the thermal treatment50may include a rapid thermal process. According to an embodiment of the present invention, the thermal treatment50may include a laser annealing process. The polysilicon gate110under the SMT film410is recrystallized by the laser annealing, thereby improving the electrical performance of the NMOS transistor.

As shown inFIG.3, after the SMT process is completed, a photolithographic process is performed to form a photoresist pattern PR on the SMT film410, and then an etching process is used to remove the SMT film410not covered by the photoresist pattern PR to form a patterned SMT film410P. According to an embodiment of the present invention, the patterned SMT film410P covers the non-silicide region of the substrate SB that does not need to form a silicide layer. Subsequently, the photoresist pattern PR is removed.

As shown inFIG.4, subsequently, on the regions not covered by the patterned SMT film410P, for example, on the gate110, the source122and the drain124of the first semiconductor device100, a silicide layer610and a silicide layer612and a silicide layer614are respectively formed. The patterned SMT film410P acts as a salicide block layer when forming the silicide layer610, the silicide layer612and the silicide layer614.

One advantage of the present invention is that the patterned SMT film410P is used as a self-aligned silicide block layer when forming the silicide layer610, the silicide layer612and the silicide layer614. Therefore, the SMT film removal step, the subsequent cleaning steps after removing the SMT film as well as the step of depositing and patterning the salicide barrier layer can be omitted, which effectively reduces the complexity and manufacturing cost of the steps of fabricating the semiconductor device.