JPS62241376A - Manufacturing method of MOS type semiconductor device - Google Patents

Abstract

PURPOSE:To simplify a process, to improve uniformity and reliability and to reduce cost by changing a gate electrode into a source and a drain having LDD structure by the formation of a side wall by accelerating oxidation. CONSTITUTION:A gate insulating film 102 is formed onto a semiconductor substrate 103, a gate electrode 101 is shaped onto the gate insulating film, and an impurity is implanted to the semiconductor substrate. When the substrate is thermally oxidized in a wet atmosphere at approximately 900 deg.C, an oxide film 106 is formed in size thicker than the silicon substrate through accelerating oxidation around the gate electrode, and an oxide film is also shaped to the side surface of the gate electrode and functions as a side wall. An impurity is implanted into the semiconductor substrate, and the semiconductor substrate into which the impurity is implnated is thermally treated to diffuse the impurity, thus acquiring an MOS type semiconductor device with source-drain 109 having LDD structure.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention provides a method for manufacturing an MO& type semiconductor device.
D D (Xrtghtly Doped Drai
Q also relates to modifying the source/drain metal shape and miniaturization of the structure (hereinafter abbreviated as LDD).

[Summary of the invention]

The present invention relates to a method for manufacturing a MOB type semiconductor device, in which an oxide film is formed around the gate capacitor by thermally oxidizing the gate capacitor after impurity implantation, and an LDDI QMOS type is produced by further implanting impurities. It manufactures semiconductor devices.

[Conventional technology]

In the conventional manufacturing method of a CIMOB type semiconductor device, when forming an LDDi O source/drain, as shown in FIG.
L) a step of forming a gate insulating film on a semiconductor substrate and forming a gate capacitor on the gate insulating film; b) a step of implanting impurities. c) Step of forming an insulating film; d) Step of removing the insulating film by anisotropic etching so as to leave insulation on the side surface of the gate side surface. y)”y oh k (HideWal
l) and T) g) implanting impurities, f)
By heat treatment, impurities are diffused into the semiconductor substrate and % L
DD-Φ source/drain forming step 1 or more
A method of manufacturing an OB type semiconductor device + t-a was used.

[Problem that the invention seeks to solve]

However, in the conventional manufacturing method described above, it is necessary to form an insulating film on the entire surface and then remove the insulating film by anisotropic etching while leaving a side wall of the gate electrode to form a sidewall. There wasn't.

In other words, the 0 drawbacks of the conventional zmos semiconductor manufacturing method are:
l) CVD (chemical vapor growth) on O forming the insulating film
According to VC, minute control of film thickness is difficult; 2))
Due to the special etching method, the sidewall
Q conditions such as OVc uniformity are difficult to maintain so that the insulating film is not left behind. 3) It also consists of two steps: an insulating film forming step and an etching step. As a result, the process becomes complicated and the process is complicated, resulting in a combination point of 0 or more.

Therefore, the present invention, in order to eliminate the drawbacks such as one bundle,
Low temperature (900m: front slope) - By using the a method to form sidewalls by accelerating oxidation of the gate electrode in a wet atmosphere, the entire process is simplified compared to conventional technology, and the sidewall thickness is uniform. The purpose is to form it with good controllability.

[No means for solving the problem] The present invention v) MOS type semiconductor device manufacturing method is α) α)
A gate insulating film is formed on a semiconductor substrate, and a gate 1! is formed on the gate insulating film. The process of forming koshiki.

b) Step of implanting impurities. c) A step of forming an acid ratio IIa around the gate electrode by thermal oxidation and diffusing the implanted impurity into the conductive substrate.

The method is characterized by d) a step of implanting impurities; and e) a step of diffusing the impurities into the semiconductor substrate by heat treatment.

c) The above thermal oxidation is characterized by being carried out in a wet atmosphere/ambience after 900°C.

[Implementation row]

The present invention is described below.

! As shown in FIG. 1 α) O, a gate insulating film 102 is formed on a semiconductor substrate 103. Further, in this embodiment, a gate cap 101 is formed on the gate insulating film, and as an example of the gate electrode, a gate cap made of polycrystalline silicon made conductive by diffusing N-type impurities is formed. shall be. Impurities are implanted into this semiconductor substrate as shown in Figure 1b) CD. In this embodiment, phosphorus is implanted as the impurity OIHJ by ion implantation. Moreover, it is 900℃
Before pPl oxidation in flkO wet atmosphere. [Procedure 1
At this time, an acid layer [106] is formed around the gate electrode to be thicker than the silicon substrate due to accelerated oxidation.

In the case of this example, an oxide film having a thickness approximately five times that of the silicon substrate is formed around the polycrystalline silicon. Therefore, an oxide film is also formed on the sides of the 5VC gate and liM as shown in FIG. Furthermore, impurities are implanted into the semiconductor substrate as shown in Figure 1 d) 12).

In this example, this impurity is arsenic. By heat-treating the semiconductor substrate into which the Q impurity has been implanted and diffusing the impurity, the source/drain/10
A 3-type semiconductor device having an MOI of 91 was manufactured.

In the manufacturing method, oxide l formed by thermal oxidation
In II, the film thickness can be adjusted to save power by controlling the time, the uniformity is good, and the sidewall thickness can be easily adjusted, which is easier than the conventional sidewall forming method. Also, gate by accelerated oxidation! Since there is a thermal oxide film about 5 times thicker around the surface of the semiconductor, by slightly motting it with hydrofluoric acid, impurities can be implanted without damaging the sidewall thickness. It is also possible to adjust the I/L ratio.

That's it for the gate! The explanation has been given by selecting polycrystalline silicon for the base and phosphorus and arsenic for the impurities to be implanted, but if the gate is to be made of a Q material, polycide or the like can be used if accelerated oxidation is performed on the silicon substrate.

〔Effect of the invention〕

The effects of the present invention are that the source/drain of the LDD structure is formed by sidewall formation by accelerated oxidation of the gate trillc, which simplifies the process and provides good uniformity compared to the conventional VC technology. has improved reliability and lowered product costs.

[Brief explanation of drawings]

Figures 1k) to (g) are step-by-step diagrams showing the manufacturing method of the MO13M''P conductor device of the present invention. Figures 2 (α) to (a) are diagrams showing the manufacturing method of the MO13M''P conductor device of the present invention. Cross-sectional view showing the manufacturing method step by step. Oxide film 107 formed by thermal oxidation Impurity diffusion 108 Injected impurity 109 LDD structure source/drain 201 formed by diffusion by heat treatment 202 Gate Insulating film 203... Semiconductor substrate 204 element isolation film 205... Injected impurity 206... Insulating film 207... RPAC sidewall remaining after etching) 208... Injected impurity 209... Due to heat treatment Source and drain of LDD fermentation formed by diffusion Applicant: Seiko Epson Corporation 1d
+ RI Q-'

Claims (2)

[Claims] (1)a) A step of forming a gate insulating film on a semiconductor substrate and forming a gate electrode on the gate insulating film. b) Step of implanting impurities. c) A step of forming an oxide film around the gate electrode by thermal oxidation and diffusing the implanted impurity into the semiconductor substrate. d) Step of implanting impurities. e) LDD (Lightly Dope) characterized by a step of diffusing impurities into the semiconductor substrate by heat treatment.
dDrain) structure source/drain MOS
A method for manufacturing a type semiconductor device. (2) M according to claim 1, characterized in that the thermal oxidation is carried out in a wet atmosphere at around 900°C.
A method for manufacturing an OS type semiconductor device.