OBIC observation method and apparatus therefor
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorTatsuya Ishii
Life of this patent
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Abstract
In order to enable OBIC observation of a high density silicon semiconductor device provided on a semiconductor chip whose surface is mostly covered with a metal wire, i.e., for measurement of an OBIC current, the silicon semiconductor device is irradiated with a light beam from a rear surface side thereof. The wavelength of the light beam to be used has a light penetration depth, i.e., a depth for allowing light absorption of silicon (depth allowing penetration of light required for generating a photovoltaic effect) that is larger than the thickness of the silicon chip, and is shorter than the absorption edge of silicon. For example, a YAG laser beam of 1064 nm in wavelength or an InGaAs laser beam of 980 nm in wavelength is used as the light beam.
Claims13
An OBIC observation method comprising the steps of:
- (a) applying a light beam to a silicon substrate, having a first major surface being provided with a p-n junction and a second major surface opposite to said first major surface, from the side of said second major surface while performing prescribed scanning;
- (b) detecting an OBIC current fed by electron-hole pairs excited by said light beam due to a photovoltaic effect in said p-n junction;
- and
- (c) displaying distribution of said OBIC current in said silicon substrate in correspondence to said prescribed scanning,
- said light beam having a wavelength which implements a light penetration depth larger than the thickness of said silicon substrate and which is shorter than the absorption edge of said silicon substrate.
An OBIC observation apparatus comprising:
- light emitting means for applying a light beam having a prescribed wavelength;
- light introducing means for introducing said light beam into a silicon substrate, having a first major surface provided with a p-n junction and a second major surface opposite to said first major surface, from the side of said second major surface;
- scanning means for performing prescribed scanning of said light beam with respect to said silicon substrate;
- means for detecting an OBIC current fed by electron-hole pairs excited by said light beam due to a photovoltaic effect in said p-n junction;
- and
- means for displaying distribution of said OBIC current in said silicon substrate in correspondence to said prescribed scanning.
An OBIC observation method comprising the steps of:
- (a) applying a light beam to a silicon substrate, having a first major surface provided with a p-n junction and a second major surface opposite to said first major surface, from the side of said second major surface while performing prescribed scanning;
- (b) detecting an OBIC current fed by electron-hole pairs excited by said light beam due to a photovoltaic effect in said p-n junction;
- and
- (c) displaying distribution of said OBIC current in said silicon substrate in correspondence to said prescribed scanning,
- said light beam having a wavelength implementing a light penetration depth larger than the thickness of said silicon substrate.
An OBIC observation apparatus comprising:
- light emitting means for applying a light beam having a prescribed wavelength;
- light introducing means for introducing said light beam into a silicon substrate, having a first major surface provided with a p-n junction and a second major surface opposite to said first major surface, from the side of said second major surface;
- scanning means for performing prescribed scanning of said light beam with respect to said silicon substrate;
- means for detecting an OBIC current fed by electron-hole pairs excited by said light beam due to a photovoltaic effect in said p-n junction;
- and
- means for displaying distribution of said OBIC current in said silicon substrate in correspondence to said prescribed scanning.
Dependencies are inferred from the claim text.