Method for determining concentration profiles of deep levels on both sides of a p-n junction

Claim 1

A method for testing a semiconductor body which comprises: a. applying a first voltage bias across the body; b. irradiating the body under the first voltage bias, for a first predetermined period of time; c. decreasing the magnitude of the voltage applied across the body to a second voltage bias and thereafter increasing the magnitude of the voltage bias to the first voltage bias, to produce a first condition of the body; d. irradiating the body for a second predetermined period of time, to produce a second condition of the body; and e. measuring the change in electrical capacitance of the body in going from the first to the second condition.

Claim 2

A method for testing a semiconductor body which comprises: a. applying a first voltage bias across the body; b. irradiating the body under the first voltage bias, for a first predetermined period of time; c. decreasing the magnitude of the voltage applied across the body to a second voltage bias and thereafter increasing the magnitude of the voltage bias to the first voltage bias, to produce a first condition of the body; d. irradiating the body for a second predetermined period of time, to produce a second condition of the body; and e. measuring the change in electrical capacitance of the body in going from the first to the second condition.

Claim 3

A method for testing a semiconductor body which comprises: a. applying a first voltage bias across the body; b. irradiating the body, under the first applied voltage, for a first predetermined period of time; c. decreasing the magnitude of the voltage applied across the body to a second voltage bias and thereafter increasing the magnitude of the voltage applied across the body back to the first voltage bias, to produce a first condition of the body; d. irradiating the body for a second predetermined period of time, to produce a second condition in the body; and e. developing an electrical signal indicative of the difference in electrical capacitance of the body going from the first to the second condition.

Claim 4

A method for testing a semiconductor body which comprises: a. applying a first voltage bias across the body; b. irradiating the body, under the first applied voltage, for a first predetermined period of time; c. decreasing the magnitude of the voltage applied across the body to a second voltage bias and thereafter increasing the magnitude of the voltage applied across the body back to the first voltage bias, to produce a first condition of the body; d. irradiating the body for a second predetermined period of time, to produce a second condition in the body; and e. developing an electrical signal indicative of the difference in electrical capacitance of the body going from the first to the second condition.

Claim 5

A method for testing the neighborhood of a P-N junction of a semiconductor, comprising the steps of: a. applying a reverse bias voltage VR across the P-N junction in order to produce a depletion region in the neighborhood of the junction; b. irradiating the junction with optical radiation of wavelength and intensity sufficient for producing a condition of the junction throughout the first depletion region produced by the bias voltage VR, said depletion region characterized by a first predetermined ratio of deep levels which are empty of charge carriers to deep levels which are filled with charge carriers; c. varying the reverse bias voltage (in the absence of said optical radiation) from VR to a predetermined value V and then back to Vr, said value V corresponding to a second smaller width of the depletion region, in order that the junction be in a second condition characterized by a second predetermined ratio of deep levels which are empty of charge carriers to deep levels which are filled on the N side of the P-N junction in the semiconductor between the edges of the first and second depletion regions, and characterized by the first predetermined ratio elsewhere in the first depletion region; d. irradiating the junction with optical radiation for returning the junction into substantially the first condition; and e. measuring the difference in electrical capacitance C2 across the junction going from the second condition to substantially the first condition.

Claim 6

A method for testing the neighborhood of a P-N junction of a semiconductor, comprising the steps of: a. applying a reverse bias voltage VR across the P-N junction in order to produce a depletion region in the neighborhood of the junction; b. irradiating the junction with optical radiation of wavelength and intensity sufficient for producing a condition of the junction throughout the first depletion region produced by the bias voltage VR, said depletion region characterized by a first predetermined ratio of deep levels which are empty of charge carriers to deep levels which are filled with charge carriers; c. varying the reverse bias voltage (in the absence of said optical radiation) from VR to a predetermined value V and then back to Vr, said value V corresponding to a second smaller width of the depletion region, in order that the junction be in a second condition characterized by a second predetermined ratio of deep levels which are empty of charge carriers to deep levels which are filled on the N side of the P-N junction in the semiconductor between the edges of the first and second depletion regions, and characterized by the first predetermined ratio elsewhere in the first depletion region; d. irradiating the junction with optical radiation for returning the junction into substantially the first condition; and e. measuring the difference in electrical capacitance C2 across the junction going from the second condition to substantially the first condition.

Claim 7

A method for testing a semiconductor body which comprises the steps of a. applying a reverse bias voltage VR across the P-N junction in order to produce a first depletion region having a first width in the neighborhood of the junction; b. irradiating the junction with optical radiation of wavelength and intensity sufficient for producing a first condition of the junction throughout the first depletion region characterized by a first predetermined ratio of deep levels which are empty of charge carriers to deep levels which are filled with charge carriers; c. varying the reverse bias voltage (in the absence of said optical radiation) from VR to a predetermined value V and then back to VR, said value V corresponding to a second smaller width of the depletion region, in order that the junction be in a second condition characterized by a second predetermined ratio of deep levels which are empty of charge carriers to deep levels which are filled with charge carriers on the N side of the P-N junction in the semiconductor between the edges of the first and second depletion regions and by the first predetermined ratio elsewhere in the first depletion region; d. irradiating the junction with optical radiation for returning the junction into substantially the first condition; and e. developing a first electrical signal indicative of the difference electrical capacitance of the junction going from the second to substantially the first condition.

Claim 8

A method for testing a semiconductor body which comprises the steps of a. applying a reverse bias voltage VR across the P-N junction in order to produce a first depletion region having a first width in the neighborhood of the junction; b. irradiating the junction with optical radiation of wavelength and intensity sufficient for producing a first condition of the junction throughout the first depletion region characterized by a first predetermined ratio of deep levels which are empty of charge carriers to deep levels which are filled with charge carriers; c. varying the reverse bias voltage (in the absence of said optical radiation) from VR to a predetermined value V and then back to VR, said value V corresponding to a second smaller width of the depletion region, in order that the junction be in a second condition characterized by a second predetermined ratio of deep levels which are empty of charge carriers to deep levels which are filled with charge carriers on the N side of the P-N junction in the semiconductor between the edges of the first and second depletion regions and by the first predetermined ratio elsewhere in the first depletion region; d. irradiating the junction with optical radiation for returning the junction into substantially the first condition; and e. developing a first electrical signal indicative of the difference electrical capacitance of the junction going from the second to substantially the first condition.

Claim 12

A method for testing a semiconductor body containing a P-N junction which comprises: a. optically irradiating the body, under a first voltage bias applied thereacross, for a first predetermined period of time to produce a first condition in the body, said irradiating being sufficient to effect an emptying of a predetermined proportion of deep impurity levels in a given neighborhood of the P-N junction; b. decreasing the magnitude of the voltage applied across the body to a second voltage bias and thereafter increasing the magnitude of the voltage applied across the body back to the first voltage bias, to produce a second condition of the body; and c. developing an electrical signal indicative of the change in capacitance of the body going from the first to the second condition.

Claim 13

A method for testing a semiconductor body containing a P-N junction which comprises: a. optically irradiating the body, under a first voltage bias applied thereacross, for a first predetermined period of time to produce a first condition in the body, said irradiating being sufficient to effect an emptying of a predetermined proportion of deep impurity levels in a given neighborhood of the P-N junction; b. decreasing the magnitude of the voltage applied across the body to a second voltage bias and thereafter increasing the magnitude of the voltage applied across the body back to the first voltage bias, to produce a second condition of the body; and c. developing an electrical signal indicative of the change in capacitance of the body going from the first to the second condition.

Claim 14

A method for testing a semiconductor body containing a P-N junction which comprises the steps of: a. optically irradiating the body, under a first voltage bias apPlied thereacross, for a first predetermined period of time to produce a first condition in the body, said irradiating being sufficient to effect an emptying of a predetermined proportion of deep impurity levels in a given neighborhood of the P-N junction; b. decreasing the magnitude of the voltage applied across the body to a second voltage bias and thereafter increasing the magnitude of the voltage applied across the body back to the first voltage bias, to produce a second condition of the body; and c. measuring the change in electrical capacitance of the body going from the first to the second condition.

Claim 15

A method for testing a semiconductor body containing a P-N junction which comprises the steps of: a. optically irradiating the body, under a first voltage bias apPlied thereacross, for a first predetermined period of time to produce a first condition in the body, said irradiating being sufficient to effect an emptying of a predetermined proportion of deep impurity levels in a given neighborhood of the P-N junction; b. decreasing the magnitude of the voltage applied across the body to a second voltage bias and thereafter increasing the magnitude of the voltage applied across the body back to the first voltage bias, to produce a second condition of the body; and c. measuring the change in electrical capacitance of the body going from the first to the second condition.