Semiconductor device and method of screening the same

• US 5,568,436 A
• Filed: 06/07/1995
• Issued: 10/22/1996
• Est. Priority Date: 05/11/1990
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Corporation
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Furuyama, Tohru
• Primary Examiner(s): Nguyen, Viet Q.
• Application Number:
  US08/480,926
• Time in Patent Office: 503 Days
• Field of Search: 365/200, 365/201, 365/230.03, 365/226
• US Class Current: 365/201
• CPC Class Codes: G11C 11/401 forming cells needing refreshing or charge regeneration, i.e. dynamic cells
• CPC Class Codes: G11C 11/4085 Word line control circuits, e.g. word line drivers, - boosters, - pull-up, - pull-down, - precharge
• CPC Class Codes: G11C 29/46 Test trigger logic
• CPC Class Codes: G11C 29/50 Marginal testing, e.g. race, voltage or current testing
• CPC Class Codes: G11C 5/145 Applications of charge pumps; Boosted voltage circuits; Clamp circuits therefor G11C5/141 takes precedence
• CPC Class Codes: G11C 5/147 Voltage reference generators, voltage or current regulators; Internally lowered supply levels; Compensation for voltage drops G11C5/141 takes precedence

Abstract

A semiconductor device comprising a plurality of circuit blocks to which various potentials, including at least one potential either raised or lowered, are assigned. The device further comprises means for selectively and reversely changing the potentials assigned to the circuit blocks.

Claims

1. A method of screening a semiconductor device which comprises a plurality of circuit blocks to which various potentials, including at least one potential either raised or lowered, are assigned, and means for selectively and reversibly changing the potentials assigned to said circuit blocks, said method comprising the step of:

selectively and reversibly changing the potentials assigned to the circuit blocks, thereby to apply a specific voltage to at least one of the circuit blocks, said specific voltage being not higher than the voltages applied to the other circuit blocks.

2. The method according to claim 1, wherein the potentials assigned to the circuit blocks are selectively and reversibly changed, such that a specific voltage is applied to at least one of the circuit blocks, which is not higher than the voltages applied to the other circuit blocks, when said semiconductor device is still on a waver.