Tokyo Electron Limited

Toyko Electron Limited

Pingshan Luan

Aelan Mosden

Christopher Catano

Hamed Hajibabaeinajafabadi

Sergey Alexandrovich Voronin

Subhadeep Kal

Yu-Hao Tsai

Matthew Flaugh

Jonathan Hollin

Selective protection and etching is provided which can be utilized in etching of a silicon containing layer with respect to a Ge or SiGe layer. In an example, the layers are stacked, and an oxide is on a side surface of the layers. A treatment is utilized to provide a modified surface or termination surface on side surfaces of the Ge/SiGe layers, and a heat treatment is provided after the gas treatment to selectively sublimate layer portions on side surfaces of the Si containing layers. The gas treatment and heat treatment are preferably in non-plasma environments. Thereafter, a plasma process is performed to form a protective layer on the Ge containing layers, and the Si containing layers can be etched with the plasma.

Selective and isotropic etch of silicon over silicon-germanium alloys and dielectrics; via new chemistry and surface modification

A method of processing a substrate that includes: positioning a substrate in a plasma processing chamber, the substrate including a layer stack of alternating layers of silicon (Si) layers and silicon-germanium (SiGe) layers, the substrate including a recess that exposes sidewalls of the Si layers and sidewalls of the SiGe layers; flowing a first process gas into the plasma processing chamber; while flowing the first process gas, pulsing a second process gas into the plasma processing chamber at a pulsing frequency; while flowing the first process gas and pulsing the second process gas, applying power to a source electrode and a bias electrode of the plasma processing chamber to generate a plasma in the plasma processing chamber; and exposing the substrate to the plasma to laterally etch a portion of the Si layers selectively to the SiGe layers and form indents between the SiGe layers.

Lateral etching of silicon

In certain embodiments, a method of processing a semiconductor substrate includes positioning a semiconductor substrate in a plasma chamber of a plasma tool. The semiconductor substrate includes a film stack that includes silicon layers and germanium-containing layers in an alternating stacked arrangement, with at least two silicon layers and at least two germanium-containing layers. The method includes exposing, in a first plasma step executed in the plasma chamber, the film stack to a first plasma. The first plasma is generated from first gases that include nitrogen gas, hydrogen gas, and fluorine gas. The method includes exposing, in a second plasma step executed in the plasma chamber, the film stack to a second plasma. The second plasma is generated from second gases comprising fluorine gas and oxygen gas. The second plasma selectively etches the silicon layers.

Plasma etching techniques

In certain embodiments, a method for processing a semiconductor substrate includes receiving a semiconductor substrate that includes a film stack. The film stack includes a first silicon layer, a second silicon layer, and a first germanium-containing layer positioned between the first silicon layer and the second silicon layer. The method further includes selectively etching the first germanium-containing layer by exposing the film stack to a plasma that includes fluorine agents, nitrogen agents, and hydrogen agents. The plasma etches the first germanium-containing layer and causes a passivation layer to be formed on exposed surfaces of the first silicon layer and the second silicon layer to inhibit etching of the first silicon layer and the second silicon layer during exposure of the film stack to the plasma.

In certain embodiments, a method for processing a semiconductor substrate includes receiving a semiconductor substrate that includes a film stack. The film stack includes first and second germanium-containing layers and a first silicon layer positioned between the first and second germanium-containing layers. The method includes selectively etching the first silicon layer by exposing the film stack to a plasma that includes fluorine agents and nitrogen agents. The plasma etches the first silicon layer, and causes a passivation layer to be formed on exposed surfaces of the first and second germanium-containing layers to inhibit etching of the first and second germanium-containing layers during exposure of the film stack to the plasma.

Growing community of inventors

Albany, NY, United States of America

Pingshan Luan