JPH02271673A - Semiconductor device - Google Patents

Abstract

PURPOSE:To improve the resistance to static electricity and to provide a high quality integrated circuit by providing a region, where no silicide is formed, on both sides of a drain and a source of an output transistor Tr of the integrated circuit. CONSTITUTION:There are provided separate regions I and II as shown by a broken line, the region II indicating an internal Tr and the region I an output part Tr. An evidenced from the figure, although in the region II a source-drain region 107 is wholly covered with Ti silicide 108, in the region I the source-drain region 107 includes a region where no Ti silicide 108 is provided. Hereby, satisfactory resistance is provided between a wiring material and a source-drain end, presenting a very strong structure a very strong structure against static electricity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor device, and more particularly to a structure of an output section of an integrated circuit including a large number of salicide transistors.

[Conventional technology]

In recent years, with the miniaturization of semiconductor devices, it has become necessary to make impurity diffusion layers that form source and drain regions extremely shallow. However, making the impurity diffusion layer shallow is
This leads to an increase in the resistance of the source/drain regions, causing a significant deterioration of the current driving ability of the transistor. In order to solve this problem, silicide is selectively formed on the source/drain and gate electrodes, and the above-mentioned source/drain
A transistor with a so-called salicide structure, which has an extremely low resistance in the drain region, has been proposed.

[Problem to be solved by the invention]

However, the above-mentioned conventional technology, that is, salicide Tr, has a problem of being extremely weak against static electricity.

Generally, the static electricity resistance of an integrated circuit is determined by the strength of the input/output parts against static electricity. The input section is protected against electrostatic discharge by means such as a protective resistor, but the output section is usually not protected against electrostatic discharge.

The strength of the output transistor against static electricity is determined by the resistance from the wiring material to the source and drain ends (gate electrode side). (If this resistance is small, electrostatic damage is likely to occur.

) Since salicide transistors have extremely low source/drain resistance, they are susceptible to static electricity.

The present invention solves these problems, and its purpose is to improve the electrostatic resistance of an integrated circuit equipped with a salicide transistor and provide a high-quality integrated circuit.

[Means to solve the problem]

The semiconductor device of the present invention is characterized in that, in an integrated circuit including a large number of salicide transistors, regions in which no silicide is formed are provided on both sides of the drain and source of the output transistor of the integrated circuit.

〔Example〕

Embodiments of the present invention will be described in detail below based on the drawings.

FIG. 1(a) is a sectional view showing a semiconductor device according to the present invention, FIG. 1(b3 is a plan view, 101 is a P-type St
A substrate, 102 an oxide film for element isolation, 103 a gate oxide film, 104 a gate electrode made of polycrystalline St doped with high concentration phosphorus, 105 a low concentration n-type impurity diffusion layer, 1
06 is a side wall spacer, 107 is a high concentration impurity diffusion layer (source/drain), 108 is Ti silicide, 109 is an oxide film for interlayer insulation, 110 is A for wiring material
It is jQ.

In addition, in FIG. 1, as shown by the broken line, the area (I) and the area (n
). The area (■) represents the internal Tr, and the area (1) represents the output section Tr.

As is clear from the figure, in region (II), the source/drain regions 107 are all covered with Ti silicide 108, but in region (I), the source/drain regions 107 are covered with Ti silicide 108.
There is a region on which Ti silicide 108 is not provided.

Next, a method for manufacturing a semiconductor device according to the present invention will be briefly described.

1) 101 to 106 are easily formed using known techniques. After forming 106, apply 100 to 300 on the entire surface.
A human oxide film is formed using chemical vapor deposition.

2) A high concentration N-type impurity such as As or P is ion-implanted, and annealing is performed in an electric furnace or a halogen lamp to form source/drain regions 107.

3) Using a photoresist pattern, leave a part of the source/drain region in the region (1) and
Remove the 0A oxide film by etching with diluted FF.

4) After forming Ti on the entire surface by sputtering 400 to 600 times, annealing is performed at around 700° C. using a halogen lamp. At this time, Ti silicide is formed on the gate electrode 104 and the source/drain region 107, but in region (I), Ti silicide is formed on a part of the source/drain region.
Ti silicide is not formed in the portion where the oxide film of 0 to 300 is left.

Furthermore, Ti silicide is not formed on the element isolation oxide film 102 or on the sidewall spacer 106.

5) Selectively remove the unreacted Ti using an aqueous solution of hydrogen peroxide and ammonia.

6) After annealing at a temperature of around 800° C. using a halogen lamp again, an oxide film 109 for interlayer insulation is formed by chemical vapor deposition, and after forming a contact hole, a wiring material 1!110 is sputtered. The semiconductor device of the present invention is completed by forming the semiconductor device by a method and performing patterning.

〔Effect of the invention〕

As described above, according to the present invention, sufficient resistance can be obtained between the wiring material and the source/drain ends, so that it is possible to provide an extremely strong structure against static electricity.

[Brief explanation of drawings]

FIG. 1(a) shows a cross-sectional view of a semiconductor device of the present invention, and FIG. 1(b) shows a plan view of the semiconductor device of the present invention. 101 ・ 102 ・ 103 ・ 104 ・ 105 ・ P-type Si substrate element isolation oxide film gate oxide film gate electrode low concentration impurity diffusion layer 106 ・ 107 ・ 108 ・ 109 ・ 110 ・ sidewall spacer high concentration impurity diffusion layer between Ti silicide layers Oxide film for insulation Ag for wiring materials Applicant Seiko Epson Co., Ltd. Agent Patent attorney Kizobe Suzuki (1 other person) (I) Yumi (1 time in total)

Claims (1)

[Claims] In an integrated circuit including a large number of transistors in which silicide is selectively formed in the gate electrode and source/drain regions,
A semiconductor device characterized in that regions in which no silicide is formed are provided on both sides of the drain and source of the output transistor of the integrated circuit.