Macronix International Co., Ltd.

Wei-Wen Chen

Yun-Chi Yang

Yaw-Lin Hwang

First of all, a semiconductor substrate is provided. Then a gate oxide layer having an uniform thickness is formed on the semiconductor substrate by way of using thermal oxidation. Subsequently, a doping layer is formed on the gate oxide layer by a plasma doped process. Next, forming a poly-layer on the doping layer of the gate oxide layer, wherein the poly-layer has an ions-distribution. Afterward, defining the poly-layer to form a poly-gate. The P-type ions are then implanted into the poly-gate and the substrate by way of using a self-aligned process. Finally, performing a thermal annealing process to form a uniform ion-implanting region and a poly-gate having a lower contact-resistance.

Method for forming a gate

First of all, a semiconductor substrate is provided, and then a photoresist layer is formed and defined on the semiconductor substrate. The pulsed plasma doping is then performed by the photoresist layer as a mask to form a doping region and an undoping region on the semiconductor substrate. After removing the photoresist layer, performing a thermal oxidation process to form a thick gate oxide layer in the doping region and a thin gate oxide layer in the undoping region. Subsequently, two gates are respectively formed on the thick gate oxide layer and the thin gate oxide layer by means of the conventional process.

Method for forming multiple gate oxide layer with the plasma oxygen doping

A method for forming shallow trench isolation is disclosed. A pad oxide layer and a mask layer are sequentially formed on a substrate. Afterwards, an opening is formed through the mask layer and the pad oxide layer such that regions of the substrate are exposed. Thereafter, the exposed regions are etched to form trenches inside said substrate. Next, nitrogen ions are implanted into the sidewall of the trenches to form a silicon nitride layer, and then a siliconoxynitride layer is formed inside the sidewall of the trenches. Subsequently, a silicon oxide layer is formed on the siliconoxynitride layer and on the mask layer. The excess portion of the silicon oxide layer over said mask layer is removed to expose the mask layer, and then the mask layer is removed away. Finally, the pad oxide layer is removed by using hydrofluoric acid (HF).

Method for fabricating shallow trench isolation

A method for forming an ultra-shallow junction by boron plasma doping is disclosed. A substrate is placed in a pulse type electric field. A flowing carrying gas drives boron ions in a channel above the substrate, and then a negative pulse type voltage is applied so that the boron ions may uniformly enter into the substrate. Then a rapid annealing process is performed so as to be formed with an ultra-shallow junction on the substrate. In the present invention, by the boron plasma doping, an ultra-shallow junction is provided on a surface of the substrate. Therefore, after the next thermal process, the property of the element can be retained. A lower depth junction is acquired, and the diffusion in the horizontal direction is suppressed.

Method for forming ultra-shallow junction by boron plasma doping

The present invention provides a method of forming different thickness&rdquo; of a gate oxide layer simultaneously, by employing a pulse Nitrogen plasma implantation. The method provides a semiconductor substrate with the surface of the silicon in the semiconductor substrate separated into a first region and a second region at least. Then a thin surface on the surface of the silicon of the first region is implanted using a first predetermined concentration of the Nitrogen ions. The thin surface on the surface of the silicon in the second region is implanted using a second predetermined concentration of the Nitrogen ions. An oxidation process is subsequently performed. The first predetermined thickness and the second predetermined thickness of the silicon oxide layer are formed simultaneously on the surface of the silicon in the first region and in the second region. The Nitrogen ions are implanted in the surface of the silicon by forming the pulse nitrogen plasma in-situ. The first predetermined concentration is not equal to the second predetermined concentration.

Method of forming a silicon oxide layer using pulsed nitrogen plasma implantation

This invention relates to a method for forming a shallow junction, more particularly, to the method for forming a ultra-shallow junction by using a arsenic plasma doping fashion. The present invention uses the arsenic plasma doping fashion to dope arsenic ions to the junction of the semiconductor and then passes through a post anneal process. The resistance value of the junction can be controlled. The present invention also uses the depth of doped arsenic ions to control the depth of the junction and to restrain the diffusion of the arsenic ions. Then the region of the junction can be reduced successfully to become a ultra-shallow junction. This ultra-shallow junction is a low resistance value and excellent electricity junction.

Method for forming the ultra-shallow junction by using the arsenic plasma

A method for determining near-surface doping concentration is provided by utilizing surface photovoltage. A monochromatic light pulse is applied to a semiconductor substrate. When the energy of the incident light is larger than the energy gap of the semiconductor substrate, the light is absorbed by the substrate and thereby generates enough charge carriers. The carriers diffuse to the surface of the substrate and result in lowering the surface barrier, and hence, cause a shift of the surface voltage. The difference of the surface voltages, before and after the light pulse applied, is measured by using a surface photovoltage probe. Then, the doping concentration near the surface of the substrate can be determined according to the difference of the surface voltage.

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Hsin-Chu, Taiwan

Wei-Wen Chen